Hi, just some suggestions here
Kantan
00:04:928 (4) - were you going to change this? I know it's just 1/1 but it's relatively fast since Kantan uses mainly 2/1 and 1/1 and 1/1 would be the fastest form of rhythm here. It's right at the start also so it just comes right at you instantly, not further down the song, it's not like 00:37:928 (48) where it's already quite into the song, so it's more familiar in terms of how fast the song goes already and some patterns would start getting to the player already
00:31:928 (36,37) - change it to k d, it would suit better here as it fits to the pitch
00:58:928 (88) - would have rather preferred beats like this that could have impact in the song have finish instead of the 1/1 beats lols, it gives people more time. Just indicating to you also this could have potential with finish cuz of the cymbals lol
01:22:928 (133) - ^
01:27:053 (141) - I actually think placing this note at 01:26:678 would be better, right now this section just feels too awkward. Especially the gap between 01:26:303 (140,141) - I know it may be weird because it won't be exactly on the vocal but the rhythm is more natural, and when I tried it, it feels better
Futsuu
00:42:990 (108) - change to d to be like 00:39:990 (100) - which does sound like it fits better
00:58:928 (159) - sounds like it could have more impact here, with the help of finish
01:10:928 (198) - ^
01:22:928 (15) - ^
Muzukashii
00:30:240 (111) - all this while, you when for kats when the vocals were higher, except this one, why not just have it as k too?
01:03:615 (265) - with the lowest pitch in the music/trumpet here, wouldn't it be better to use d?
Oni
00:42:990 (100) - like earlier, it just feels weird as kat, this really feels like a don
01:00:240 (202,203,204) - this portion of the song is more like ddk than kkd
01:12:240 (274,275,276) - ^
Good Luck~