Maison Ikkoku: Final Chapter

The Maison Ikkoku tennants throw a party to celebrate the marriage of Yuusaku and Kyouko. However, during the party Yuusaku hears that Kyouko is waiting for a letter. He becomes jealous and begins to doubt Kyouko, worrying that she still loves someone else. When the morning arrives, the answer to his worries is revealed... (Source: AniDB)