If you loved L♡DK, try Nodame Cantabile: The Movie II
A bridge between a film you've already seen and one most people haven't. Here's what they share, and what the second one does that the first one doesn't.
What they share
Both films are directed by Taisuke Kawamura, and they sit in Comedy / Romance territory. If that's the register that drew you to L♡DK, the second film will land in a comparable space — through a different lens.
What Nodame Cantabile: The Movie II is
A film about the sacrifices made in the name of classical music. Megumi "Nodame" Noda mopes around, jealous of her boyfriend's old flame. Eventually, everyone learns something about themselves.

