_Summer (アンダーバーサマー, Andābā Samā?) is an adult Japanese visual novel developed by Hook which was released on July 15, 2005 playable on the PC as a CD; a PlayStation 2 consumer console port called _Summer## followed on August 24, 2006 by GN Software. An updated version of the original game, called _Summer Renewal Edition (_Summer新装版, _Summer Shinsōban?), which is compatible up to Windows Vista and is playable on a PC as a DVD, was released on December 21, 2007. _Summer is self-described as a "laid-back school romance love comedy adventure game" (まったり純恋学園ラブコメADV, Mattari Jun Koi Gakuen Rabu Kome ADV?), according to Hook. The gameplay in _Summer follows a plot line which offers pre-determined scenarios with courses of interaction, and focuses on the appeal of the six female main characters. The story revolves around Takumi Kaizu, who after years of making good friends, many of whom are female, is asked by his best male friend Osamu Funada if he likes anyone. With his last summer in high school quickly approaching, Takumi decides to find someone to like by the end of summer vacation.

Four character light novels have been written based on the original game written by Jōji Kamio. A two-episode original video animation was produced; the two DVDs were released on October 27, 2006 and January 26, 2007. Three drama CDs were released based on the game, and a fourth was later released as a prologue to the OVA.

Source: Wikipedia