I went and read the rest over on danbooru, oh my god, I completely wasn't expecting it to be this sweet. It's not like the previous "Do Your Best, Kogasa-chan!" stories at ALL, wow. It also turns out to be a really nice take on Kogasa, Flan, and Remi? So wonderfully surprising.
Oh god, if this turns into some sort of harem, I'm going to have a heart attack, die, come back to life, and make this my favorite Touhou manga.... Oh god.... So much yas already on the second chapter!