Hilarious Then Suddenly Profoundly Sad

A real winner for this season as the small-fry Yakuza regular Gen bumps into his old English teacher in the diner, and his feelings come bubbling out - there are some real laugh-out-loud moments in the episode until right at the end, when you think the episode has ended, when Gen receives an airmail letter and suddenly certain things fall into place and the viewer is, like Gen, struck down by realisation.