Nana and Kaoru: Chapter 2.

Nana, a model student who serves as student council vice-president, and run-of-the-mill virginal high schooler Kaoru are childhood friends. They embark on regular S&M play dates in secret as a stress release for Nana. For spring break, Nana goes on a school trip to a power spot in Nagano planned by the student council. Kaoru joins her, and a change occurs in their feelings.