Haruka's younger sister, She initially sees both Takayuki and Mitsuki as older siblings until she finds out they have been seeing each other behind Haruka's back. While Haruka is in the hospital, she visits every day since there is no one else that can keep her company, even if Haruka is in a coma. This shows just how much she loves her older sister. She, like Mitsuki, is a powerful swimmer in her own right, but feels as if she can never match Mitsuki. Her intense hatred towards Mitsuki after the accident can be attributed to the feeling of personal betrayal by someone she considered an idol for throwing away her (Mitsuki's) talent and dreams as well as Mitsuki's betrayal of her sister by her sexual relationship with Takayuki. She learns to move on in life and becomes a top swimmer in Japan. (Source: Wikipedia)
Outgoing and usually the instigator of the pack, she is identifiable by the fact that she does not wear a blazer over her shirt and tie like most other characters. She likes to achieve her objectives in a straight-forward manner and doesn't really seem to mind other people's circumstances. Because she was absent during the first few days of school, she was unwittingly assigned as a member of the discipline committee. She has an older brother Kitsune, whom she apparently holds in very low regard, and an older sister Oniyuri. As she does not have a very good relationship with her family, she often runs away from her home. Due to this reason, she and Suzume missed the first few days of school as they were very far away from home on the school opening day. She's Suzume's childhood friend. She's 164cm tall and her three sizes are 81-55-82. Her name contains a kanji of tiger (虎, tora?) and the first kanji letter of her name (上) can be pronounced as 'Ue' (West), thus revealing her name's relationship with White Tiger of the West (白虎). (Source: Wikipedia)
Ritsuko Iwashita is a student in Class 2-B in Fumizuki Academy and is good friends with Mayumi Kikuiri. In Volume 1 it seems she is strong at math, but was still quickly defeated by Mizuki Himeji. In Volume 2 and the Matsuri OVA, she and Mayumi fight Akihisa Yoshii and Yuuji Sakamoto because of technical difficulties during the Summoned Being Tournament, but even with a 116-point lead on Akihisa, she loses due to his Shoukanjuu's agility and his teamwork with Yuuji. Her Summoned Being differs the most amongst the series' media. In the manga adaptation, it wears a black ninja uniform and wields a katana. In the anime adaptation, it wears Western-style armor and wields a sword. In Episode 2 of the Matsuri OVA, it has bunny ears, wears normal girls' clothing, and wields a giant hammer. (Source: Baka to Test Wikia)
Nami represents Juroujin. The two are twins and the youngest members of the club, as the only elementary students. They have a tendancy to fall over and go to sleep if they expend even the smallest amount of energy, which they seem to lack, except when they transform in which case they are full of energy. Because they represent the two gods Fukurokuju and Juroujin (who are the gods of luck and fortune) they are almost the same person. Details about the twin's relationship are in episode 6.
For betraying Jesus Christ, Judas Iscariot has been cursed to roam the Earth endlessly, unable to touch another human ever again. To get his body back, he must take the lives of 666 people. To carry out this task, he uses a 'vessel.' Whenever the vessel bleeds, Judas comes out and uses his power of Death through the vessel, in order to take a soul. His character is that of an arrogant, perverted bully. He likes bullying his current vessel, Eve, and enjoys nothing more than reading a nudie mag with a glass of scotch on the side. Normal people can't see Judas, only when they are already on the verge of death or have seen him appear from Eve, can they see him float around Eve and interact with him. Being the one who betrayed Christ and bringing nothing but Death wherever he goes, he is hated even by his fellow Apostles. But in the end, this man with the 'Serpent Eyes' turns out to be nothing more than a human whose emotions just got the better of him. Eventually, he plays a vital role in the destiny of humankind, but will he be able to find his own salvation?
A secretary at Makoto's office. Tries to seduce Makoto, however, fails.