Chiyo Iin

Age: 12
Birthday: October 1st (Libra)

A 1st year student at Ohananomitsu Middle School and is Aijou Rentarou's cousin, she is also the class president of her class.

She is Aijou Rentarou's 12th girlfriend.

Chiyo is reliable and tidy which is what led to her becoming class president. But she dislikes negative things such as violating the rules, looking untidy, a messy room, rude speaking, porn mags, underage smoking, etc. As soon as she sees something untidy, she can't help but immediately fix it.

When she takes her glasses off, she becomes incredibly anxious and begins crying uncontrollably.

Name/Birthday Pun Explanation:

Iin (伊院) is made of 伊 (Italy, but may also refer to 伊呂波, meaning "fundamentals") and 院 (institution, or school).

Chiyo (知与) is made of 知 (wisdom) and 与 (to participate, or award).

Chiyo's full name is written in hiragana strongly resembles the second half of the Japanese word for "class president" 学級委員長 in hiragana, referring to Chiyo"s position at school.

Chiyo's name: いいんちよ, iinchiyo.

Class president (学級委員長) in Japanese: がっきゅういいんちょう, gakkyuu iinchou.

Chiyo's birthday is on October 1st. This day is also known as 'Glasses Day (メガネの日 Megane no hi)' in Japan due to the number '1001' looking like a pair of glasses.

(Source: 100Kanojo Wiki, edited)