Should you watch S2 of Masamune-kun if you have watched S1 when it originally aired? I think yes. It definitely improves upon the first season's not all too special plot, by means of some random but pretty funny twists, while keeping the already good parts good, like the great MC. Moreover, it does a good job reintroducing the side characters. The theme songs are alright but can't quite match up to WAGAMAMA MIRROR HEART. Occasionally, the plot tries to be too grandiose for its own good, and I wouldn't call it a must-watch, but it was always entertaining, never boring. I am looking forward toS3 in 2030 ;)