Two main leads didn't share that spark (or I haven't noticed it). Perhaps authors wanted to go for realism (you might never know with whom you fall in love!), but it didn't work.

The movie was unnecessarily long and slow, there were too many empty scenes (look, bland spring scenery!), which were supposed to let viewers think about the character's decisions. But truth be told, there wasn't much to think about. There weren't even many memorable moments between our leads. Sometimes it felt, that scriptwriter had material only for 50 minutes (and this movie would've worked better as an episode 1).

The characters were alright, but I didn't care about them (This movie had 100 minutes to make me care and yet they failed).

Mitsuomi - Shy, yet caring, also want to inherit the family business. As the story progresses he becomes more genuine.

Yamato - happy-go-lucky, always wears a smile on his face, yet is clueless about social interaction. Hides pain and loneliness behind the smile (cliche, but when done right can become interesting, yet this time it was the only cliche, which was said, like exposition by other characters TWICE).

The movie had a flashback scene, it tried to symbolize how our character falls in love, but it felt lazy. The ending didn't feel organic either. Everything wrapped up so quickly. Am I supposed to believe that Yamato decided so quickly? So perhaps it didn't mean that much to him, after all? These are interesting questions, which showcase depth in characters. Pity we wasted our time on those bike rides and didn't provide the main couple with meaningful scenes. (there were plot-points, but they were just plot points).

Look, don't waste your time and grab some manga, webtoon, or check out Kinou Nani Tabeta? which shares a similar dynamic, but there characters have CHEMISTRY. Or if you want laid back stories try Rental Nan mo Shinai Hito.