You must have watched a completely different movie as there's really nothing overtly angsty nor melodramatic about the fairly youthful and carefree tone The Ocean Waves takes in spite of it's subject matter (bullying and divorce). It's an incredibly restrained and naturalistic work, especially when compared to hamfisted tripe like Shigatsu, AnoHana, that awful pa works fish thing, and the dime-a-dozen trash romcom harem LN adaptations that are all the rage these days.
It's by no means a masterclass Ghibli work like Cagliostro, Kiki's, Only Yesterday, Yamadas, or Whisper of the Heart, and it's lacking visually and musically in comparison thanks to it being a project for the younger peeps at Studio Ghibli but it's still a really nice and memorable movie in spite of all that. Easily a far more worthwhile experience than the lesser Ghibli things like earthsea, cat returns, howls, arrietty, poppy hill and most definitely marnie going by critical reception.