A new school term begins, as does the season of new encounters. As he surveys his class full of couples, Hashiba Jun'ichi's mind is filled with distress as he asks himself, "Why am I still a virgin?!" Having heard from his friends that the easiest way to fulfill his long-standing desire to graduate from the fellowship of virgins is to kowtow to a gal, Jun'ichi does exactly that and asks his classmate Yukana out. And unbelievably, she actually agrees to date him. What will become of Jun'ichi from now on?
Shinya Yukimura and Ayame Himuro are two scientists that want to find out if love can be solved by a scientific theory. These two scientists also have feelings for each other and want to be able to solve their feelings through similar theoretical facts. With this perfect opportunity, these scientists will attempt to solve the theory of the love they express for each other.
A continuation of the epic adventure of plucky Riko and Reg who are joined by their new friend Nanachi. Together they descend into the Abyss' treacherous fifth layer, the Sea of Corpses, and encounter the mysterious Bondrewd, a legendary White Whistle whose shadow looms over Nanachi's troubled past. Bondrewd is ingratiatingly hospitable, but the brave adventurers know things are not always as they seem in the enigmatic Abyss.
