Itsuka Dokoka de.

The follower-up to the first Erotic Baka Novel game is similar to it in structure: it is a visual novel with multiple story lines, which take place according to the decisions made by the player during the game. The protagonist is once again a regular Japanese male; this time, the initial "trigger event" is a message on his pager. Three different choices regarding his reaction to the beeper's sound lead to three very different story arcs, each involving its own sub-branches.

[From Moby Games]