How to unlock friendship events to naruto ultimate ninja storm2?

To begin, some characters are different, but only to begin, then the rest is the same. Sometimes you'll do a request or a miision with a character, and upon completing the mission, thier friend gauge will fill (1 heart out of 5).

Once they have at least 1 heart, they will send you mail. There will be 3 from each character total. You will be given two choices to respond with. If you pick the right one, the friend gauge for that character will increase by 1. If you get it wrong, it will not increase. Since there are only 3 letters, you can only get up to 4 out of 5 hearts. Just gift them a ninjutsu book (for males) or flowers (for females) to get the fifth heart, and any other hearts you lost answering incorrectly.

If you don't get to do a mission with that character, give them a gift to raise thier hearts to 1, then they will mail you as usual.

Once you filled a characters hearts to 5, you can activate thier Friendship event. Just find them somewhere in the hidden leaf village with a heart icon above thier head. For some characters, you need to get the friendship events for multiple people, for example you have to have Ino at max to unlock TenTen and sakura or sai's event.

A cutscene will play and you will unlock the 2 alternate support styles for that character. Unlock them all and snag yourself a trophy and a title.