[3][4] The series is produced by David Production and chief directed by Takahiro Komei, Hideya Takahashi, and Yasuhiro Kimura, with Yūko Kakihara as head writer, character designs and season 1 chief animation direction by Naoyuki Asano, and Masaru Yokoyama composing the music.

[5][6][7] Sentai Filmworks has licensed the series in North America, Europe, Oceania, and selected Latin American and Asian territories.

Since the class is equally divided between male and female students, the election ends in a draw, and Shutarō decides to settle the result with a duel.

Bedridden with a cold, Ataru is visited by his classmates Shinobu, Shutarō, Satoshi (Megane/Eyeglasses), Kōsuke (Perm), and Akira (Chibi).

While hanging out with Lum, Shinobu, Shutarō, Cherry, and Sakura at one of the Mendō family's hotels, Ataru finds a water-dwelling yōkai secretly living at the bottom of the pool.

During the school's sports festival, Ataru hits on Ran, a childhood friend of Lum, who transferred to the class next door to take revenge over a boy they both liked in the past.

Shutarō's mischievous younger sister, Ryoko, visits him at school and catches Ataru's interest, causing much mayhem.

Irritated that his parents are overjoyed at having Lum living with them, Ataru storms out of the house and finds her little cousin Ten in the mailbox.

Later, they go to Sakura's temple for the New Year, where they meet with Cherry, Shinobu, and Ran, who is working there part-time and does some quick thinking to keep secret that she is an alien.

The school decides to crakdown on snacking during lunch time, and post teachers at the students' favorite spots to catch them.

During a baseball game at the Tomobiki High School's sports tournament, Tobimaro Mizunokoji shows up to challenge Shutarō because of a childhood incident.

Tobimaro's skills and meddling from Shutarō's sister, Ryoko, make for a memorable game... After Rei eats a crumb of taiyaki off Ran's cheek, she mistakes it for a kiss and assumes he is over Lum.

On one of the last days of Summer, Lum, Shinobu, Ataru, and Shutarō meet the Fujinami family, a father and a teenager, running the only open seaside café on the beach.

After learning of a mining operation on a planet with a secret from when they were in elementary school, Oyuki meets with Lum, Benten, and Ran about their revenge attempts on their old robotic teacher, CAO-2.

While he rushes to get another jar to turn her back to normal, she tells Ataru that the only way for her to regain her regular size is for him to shower her with love and affection.

When the Principal of Tomobiki High is knocked unconscious in his office, suspicion immediately falls on the school's most infamous troublemakers!

Nagisa has moved in with Ryunosuke after gaining physical body, drama and battle ensues between a boyish girl and a girlish boy.