Does it have to be fantasy?
No, other genres is okay. It's just I'm in mood for long story fantasy recently
Reimei no Arcana
Then read this.
http://www.mangago.zone/read-manga/watashitachi_no_shiawase_na_jikan/
Get some tissues before reading it.
Highly second this. Perfect definition of tear jerker
Can someone recommend drama fantasy manga that make you cry everytime you read it? But it has happy ending, even if still ongoing it's okay