Analtagonist's Favorite

If you NEED to know if this has a happy ending or not
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It's a happy, yet not shown ending. It's established that Kou came to Shirou, summoned by the toy plane showed in the very first chapter. Kou wanted to go back to apologize to Kikujiro (grandpa) for disappearing without saying goodbye, and ask him to please have a great life and not to worry about him; basically he wanted to make things clear because grandpa was miserable all his life and that reflected on the rest of his family, and Kou wanted Shirou's family, and thus Shirou, to be happy. Kou goes back as he promises he'll be back, they hug, and Shirou makes the toy plane fly as Kou disappears.
Sometime later (not established, but not long after) you can see Shirou with a picture of his happy family in the background. He goes to the lake with the toy plane, throws it, and says "it's my turn to be greedy now...Kou" and it ends, implying that Kou got summoned again.
I've never read a Syaku manga with a sad ending, they just like writing those kinds of melancholic, complex stories, even with GinHiji doujins.

Does anyone know how to upload a comic onto this website? There's a webtoon that I'm reading that's not on this site and I want everyone to read it too.