The Irregular at Magic High School, Vol. 5 (light novel): Summer Vacation Arc +1 (Volume 5) (The Irregular at Magic High School, 5);

After the conclusion of the Nine School Competition, summer arrives in force, bringing with it that most precious salvation for students--vacation! Shizuku invites Tatsuya, Miyuki, and their friends to her family's island villa for a bit of fun in the sun, but all of this is just a pretext to set the perfect tropical stage for Honoka's romance. Meanwhile, the ace of Third High, Masaki, entertains Kichijouji at home, unaware of his partner's struggle with self-doubt. Shun finds himself playing bodyguard to a beautiful foreigner, and Eimi is cornered for a secret she can't reveal at any cost. The one who's got it toughest, though, is Mayumi, who's desperate to find the next student council president before time runs out!