 If you liked
Boku to Kimi no Taisetsu na Hanashi
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 ...then you might like
Kaoru Hana wa Rin to Saku
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Both mangas give a simmilar wholesome vibe. I think it is because they're both slice of life stories that focus on the slow but sure development of the relationship between the protegonist as they evolve in their own way.
Both mangas also show friendship and the importance of communication in relationships.