Ebina Nadeshiko

Weakness: Smell. Gets really turned on by her younger brother's scent.

The protagonist's older sister who calls him "Tsukkun". Has an extreme brother complex. She had gone overseas to study, but returns back home at the start of the game. Even though she had already completed her high school studies overseas, she is allowed to attend their school as a third-year.

Her personality and the things she says are often wild surprising those around her, coupled with her carefree attitude people tend to think she is a bit of a fool but she is actually quite intelligent. However, due to her personality, she is also quite popular and always has a fan club dedicated to her following her during break times.

Spoiler

She is always making dirty jokes so people think she is a slut but in fact she is a virgin. She used a drug recomended by Ayame to have sex with Tsukushi the night before she left overseas, but he forgets it and when he has sex again when she comes back he assumes she's not a virgin because she really had other partners, which is not true.

"Yeeees~ It's me, your lovable and dear Nadeshiko-onee-chan! Long time no see, Tsukkun!"