Kotegawa, Nanaka

Nanaka is a very beautiful young woman with waist-length brown hair that has bangs hanging over her face, reddish-brown eyes, a very voluptuous figure with large breasts.

When not working as an instructor, she is usually seen in casual clothes, like dresses.

Nanaka is a very sweet, caring and nurturing woman who takes the role of the mother hen within the group. She doesn't usually take part in the group's drinking and partying, preferring to observe. Like Chisa Kotegawa, Nanaka loves diving and is a diving instructor. She has a very severe sister complex when it comes to Chisa and the only time in which she sheds her sweet image is when it comes to Chisa, particularly in relation to Iori Kitahara. Whenever Iori is mentioned to be Chisa's boyfriend, Nanaka becomes very hostile, frightening, and threatening, and would even resort to violence if necessary.