In School Days, there are twenty-one possible endings for the player to experience. There are fifteen good endings where the main character ends up with one of the obtainable heroines in the game. Of these endings, seven good endings are devoted to Kotonoha, five are given to Sekai, two are for Hikari, and one is with Otome. Of the other six endings, two are harem endings where the main character ends up with multiple girls. In one of these two, Sekai and Kotonoha both get together with Makoto, and in the other, Makoto has sex with various girls almost every day. There is one ending in the game which is only made available when certain conditions are met for one of Kotonoha's or Sekai's good endings entitled "Carnal Desire" (Kotonoha) and "Bavarois" (Sekai) where Makoto ends up getting Setsuna pregnant.
The final three endings featured in the game are the three bad endings which involve the death of one of the three main characters (either Makoto, Sekai, or Kotonoha) in violent circumstances. In one of these endings, Kotonoha kills Sekai in broad daylight with a saw to the neck; in another, Sekai stabs Makoto for leaving her for Kotonoha; and in the last bad end, Kotonoha kills herself by jumping off Makoto's apartment building after he chooses Sekai.
The PlayStation 2 version of School Days features five new endings, all of which involve the death of one of the main characters. Four of these endings involve a single death each where Makoto dies in one, Kotonoha dies in one, and Sekai dies in two of the four. The fifth ending involves the deaths of both Kotonoha and Sekai.