1-1. I'm Lum the Notorious! This episode opens with a baseball game and Ataru getting hit with a left field flyball. Ataru is soon escorted home and discovers he's been chosen to fight an invading alien force's champion in a 10-day game of tag. If he loses, the aliens will invade. But if he wins, the aliens will go home. Ataru isn't at all willing to play tag until he sees the alien's champion: the beautiful Lum. 1-2. It's Raining Oil All Over Town This episode opens with Ataru friends Megane and Lum's Stormtroopers at school who are watching films of the tag game. In this episode, a space taxi gives Ataru a ride home by accident and the fee is...too much. Since Ataru cannot pay, the space Taxi Collection Agency starts stealing all the oil in the world.

2-1. Space Mail Arrival of Ten-chan! This is the first episode with Jariten, Lum's cousin. Jariten arrives in a giant peach and he and Ataru are enemies at once. 2-2. Mrs. Swallow and Mrs. Penguin This episode opens with Lum putting on makeup to go meet Darling at school. A swallow swallows some food Jariten gives it and it grows such that it looks like a penguin. It's appearance in school is just the start of a full day of panic.

3-1. The Metamorphic Handsome Man Rei is Here! This show features the first appearance of Rei, Lum's former fiance. This episode opens with Ataru in his room watching a storm, and Lum trying to coax him to bed. Shinobu meets Rei and brings him to Ataru's house. After a lot of arguing, Rei challenges Ataru to a duel for Lum. 3-2.Drop Dead, You Lady-Killer! Ataru, Megane, and friends are going to a Gyudon restaurant for lunch and are quite shocked to see Rei munching down food like a black hole. During the rest of the episode, Rei is chasing Lum, Ataru and friends and as the chase goes on, the chaos grows on.

4-1. Kintaro of the Autumn Sky First episode with Kintaro, the vicious little boy with the pet flying bear and the red haired alien nanny. Lum and Jariten meet Kintaro inside a wind carp, and Kintaro tells them he's was looking for his nanny in the carp. Ataru, Shinobu, Lum, and Jariten try to help Kintaro find his nanny by asking around. 4-2. Live Vigorously! Kintaro's nanny, with Ataru's help takes the alien children on a tour of Earth and a Earth child's school. Ataru tells the myth of the real Kintaro who grew up in the wild and slew a demon. So Kintaro decide to live up to his name.

5-1. The Mysterious Seductive Beauty Sakura First appearance of Sakura, The Shinto maiden. Ataru can no longer endure Lum, so he has gone undercover. Unfortunately, at a restaurant, the appearance of Lum, Ataru parents, Shinobu, and Cherry blows his cover; and a mob chases after him. He manages to duck them and bumps into Sakura, who takes him home for exorcising. 5-2. Tormenting Virus Arriving at school one morning, Ataru is greeted by all boys in the school who are waiting for the new nurse, Sakura, arriving at school today. Ataru appears to be sick, but in reality he is possessed; and Sakura performs the exorcism.

6-1. Love Triangle Black Hole Ataru is phoning Shinobu in order to make plans for a date, when Lum interrupts and get's Shinobu mad at Ataru. Ataru throws Lum out and spends the rest of the episode trying to contact Shinobu. But Lum is persistent and uses a ray to jam the phone lines. But this ray also has the side affect of making a plane and a helicopter vanish. 6-2. Hey Hey, It's a Little Demon Walking home from school, Ataru is assaulted by a group of black cats and gets a nasty bump on the head. At midnight, he is using two mirrors to look at the bump, when a little demon pops out of the mirror. The demon proves to be too much for Ataru and Mr. Moroboshi, so they get Cherry to exorcise it.

7-1. The Scary Electric Shock! Cherry gives Ataru some yellow ribbons which when tied to her horns, negate Lum's powers. In order to coax Lum into wearing them, Ataru has to put on a big charade of really loving her. 7-2. The Doll of Ill Will After an odd loss of control of his body after dinner, Ataru finds out Lum has some clay for making voodoo dolls. Ataru takes full advantage of the situation until Lum make a doll of Shinobu, and Ataru tries to get it away from Lum.

8-1. Neptune Beyond the Closet First appearance of Oyuki, Lum friend and queen of Neptune. Oyuki also has incredible ice powers. Megane and friends visit while Shinobu is nursing Ataru, who has a cold; and they discover a gate to Neptune in Ataru closet. By accident, they go through this gate and arrive on Neptune to be greeted by Lum and Oyuki. 8-2. The Confusing Dinosaur Age While Ataru is flying an ultra-light, with Lum and Jariten tagging along, Kintaro crashes into him. With the help of Lum's electric shock, the crash send them all back in time to the dinosaur age.

9-1. Sleeping Beauty Princess Kurama First episode with Kurama, the karas-tengu princess. On a field trip, Ataru and friends accidentally meet a karas-tengu who takes Ataru to marry Kurama. Kurama then tries to reform Ataru to be her perfect husband. 9-2 Athletic Woman Hell! Kurama uses a weird dimensional door to try and cure Ataru of his lechery. Inside the door, Ataru faces hostile versions of the girls he loves.

10. Pitter-Patter Christmas Eve Megane and Lum's Stormtroopers set up a plot to embarrass Ataru and get Lum to leave him at the same time. They set up a date who will make a fool of Ataru, but Lum finds out and twists things around.

11. Ataru Genji Visits Heinkyo First appearance of Mendo, the rich noble; but it is not until episode 27 that he really does anything. Mendo tells a tale about ancient Japan featuring the normal cast in a slightly different alien invasion story. The aliens this time, all look like a bunch odd barbarians, except for a pretty girl and her young boy cousin.

12-1. Love Battle Royale First appearance of Tsubame, Sakura's boy friend who has some magic abilities. Sakura invites Ataru, Lum, Shinobu, Megane, Perm, Chibi, and Kakugari to a disco. Things later go haywire as Tsubame starts casting spells and all sorts of weird creatures appear, including Rei. 12-2. Father, You Were Strong Kurama takes Ataru back in time to help her father who appears to be afraid of women. Later Ataru and Kurama's father have to get past a guard on a bridge.

13-1. Hawaiian Swimsuit Thief Ataru, Lum, Shinobu, Sakura, Megane, Cherry, and others are staying at a beachside resort. During the day, an octopus is stealing peoples swimsuits, but it appears to look like Cherry is doing it. At the end, they find the octopus and beat him up. 13-2 Full Course from Hell Still at the resort, the group meets some maniac who is having an all-you-can-eat contest. Sakura reveals the secret of her figure to be a diet pill called ""Beauty Foods."" But we really know the real reason is Sakura can just plain eat like a whale, and we see her do so as she beats Ataru and Cherry in the contest and clean the maniac of all his food.

14-1. Mendo Arrives With Trouble! Mendo returns for a formal introduction on his first day at school. He and Ataru have a duel for presidency of the class which ends in a tie. So they have a duel with cannons, which Ataru wins with help from Lum. 14-2. Constellation-Go-Round Lum's computer tells her that Mendo is really the best choice for her lover, so she brings a set of constellation scales to school and weight Ataru versus Mendo in a series of test in the scales. At the end, the scales break and we see the class as constellations.

15-1. Great Kiss War First appearance of Benten, Lum's best friend the goddess. Lum takes Ataru to another planet to help in a battle against Benten's family. The battle consists of catching stones in bowls on a giant set of scales. Ataru starts playing with Benten and ends up messing up the entire game. 15-2. The Benten Corps' Return Match Benten and her girl biker friends come to Earth for another round of fun. Ataru sides up with Benten again, and Lum recruits Jariten and some people dressed as demons.

16-1. Oh, Lonely Teacher! First appearance of Kuribayashi Sensei Ataru and Kuribayashi are enemies from the very start. Then Lum shows up and Kuribayashi falls in love. Finally Lum goes out with Kuribayashi in hopes on lightening his spirits. 16-2. Terrible Inspection Day On a day when students mothers come to school, Mrs. Mendo and Lum's mother get into a dispute and Mrs. Moroboshi acts as judge by setting up a roulette game.

17-1. Fourth Dimensional Camera Mendo bring an antique camera to school that sends Ataru off into other worlds. Lum manages to find him through a class room window that had been stuck for years. 17-2. Demonic Jogging Every morning, Ataru goes jogging early to see girls. On the way to school, Ataru breaks the fall of an attempted suicide as he was grabbing for a 100-yen coin below her. Ataru and Mendo get into a dispute over who is more noble and end up playing a game of tennis.

18-1. Girl's Day! Ran-chan's Arrival First appearance of Ran, Lum's childhood friend. During a small celebration at the Moroboshi house, a little doll enchants Ataru to follow it to Ran. Ran tries to kiss Ataru to drain his youth, but Lum shows up. 18-2 Ran-chan's Introduction Ran invites Lum, Ataru, and Ten over for cookies and tea, but her real plot is to suck Ataru's youth. Ran makes a double of Ataru and tries switching them, but she gets confused and loses the real Ataru.

19-1. Diary of Sorrowful Tomorrows Lum acquire's Ataru's diary that has written in events that will happen throughout the day. Ataru tries to use it to his advantage, but the records in the diary are not quite how they first read; making use of puns or ambiguous statements. 19-2. Whose is this Child? Mendo finds an alien child in his locker and goes through great lengths to hide it from everyone. Later after everyone has found out, a whole mob of these alien children arrive, just for Mendo.

20-1. Sleeping in Class on a Wonderful Spring Day During math class, Kuribayashi and all the students fall asleep, save for Ataru and Mendo. Lum arrives and finds out that a tiny old man and girl are responsible for this magic. The tiny girl then uses some more magic to have a party with Lum, Ataru, and Mendo; until the principal arrives with some parents. 20-2. Peach Blossom Poetry Contest Lum, Mendo, Shinobu, Ran, Ten, Sakura, and Cherry all are in a blossom orchard for some traditional reason. Ataru is in the blossom orchard for a picnic. Cherry's chanting summons some sort of woman spirit, whom Ataru runs off and meets with a giant.

21-1. Duel! Ataru vs. Ataru Ataru eats a lollipop Lum gave him and gets a mouth burn. Running off, he finds Cherry and a weird melon, which Ataru eats to cool his mouth. The melon causes Ataru to split into two Ataru's, one polite and the other casual. The two continue to fight all day. 21-2. Waking to a Nightmare Sleeping in class, Ataru has weird dreams which he relates a little of as he occasionally talks in his sleep. Annoyed, his classmates wake him and a dream demon comes out from Ataru's sleep.

Lum returns to her home planet unaware that her father is throwing her a matchmaking party. Ataru (who knows about the party) and Ten follow her.

On a school field trip, Ataru gets involved with Kappas, and a limestone cavern reveals Mendo's greatest weakness.

Ataru and Ten switch bodies after wearing special earmuffs.

Ataru becomes the owner of a white caterpillar with a ravenous appetite.

Ten develops an unrequited crush on Sakura.

Dracula arrives in town and sets his sights on Lum as his next victim.

Lum travels back in time in order to meet a younger Ataru and cure his libido.

Ataru and Ten compete for the attention of the pretty female proprietor of a flower shop.

The gang meets Tsuyuko, a girl who seems to bring rain wherever she goes.

Ten's horn falls off during a fight with Ataru, leaving him weak and unable to breathe fire. Ataru wastes no time in taking advantage of the situation.

Chaos ensues at the library after the characters in the books start coming to life. Wendy Darling (from J.M. Barrie's Peter Pan novel) enlists Ataru and Lum's help in restoring order.