Three stories.
1. A guy ends up communicating with another guy three years in the past through notes in a magic tin. Present guy (2013) and past guy (2010) promises to meet each other once the past guy gets out of the hospital. It's genuinely cute and I love the fact that it was his own friend the entire time. Fav story.
2. Senior is delighted when his childhood friend finally goes to the same school he does. But he gets troubled once he found out the junior actually likes someone. Meh.
3. Two friends with a large age gap once made a promise once uke turns 15, they can get married. Now uke is 15 and the seme wonders if he even remembers. When uke confessed, he was 5 and seme was already in high school. Meh.
Samishigariya no Love Letter