My bad, turns out, I don't like the song :v Here though, I modded your kantan at least, and....there was a lot to do
Kantan
00:04:067 (4) - Should probably be k to avoid monotony
00:07:877 (8) - Same thing as ^
00:12:162 (12) - Same concept, just make it d (lmao)
00:16:448 (17,18,19,20,21) - Too monotonous, try d k d d k (I get that Kantan is supposed to be easy, but it's not supposed to be boring)
00:20:734 (23) - This might sound better as a d, your opinion though, after all, it's Kantan
00:23:115 (26) - Making this a k will follow the song better
00:28:829 (34) - Make this a k for reasons mentioned before
00:48:829 (67) - K K K K K K K is WAAAAAY too repetitive at this length, make this a D
00:52:639 (71) - ^^^^^^^^^^^^^^^^
00:56:448 (75) - ^^^^^^^^^^^^^^^^
00:58:353 (77,78,79,80,81,82,83) - Probably should be D D K K D K D
01:06:924 (90) - This should be a k, mono color is still repetitive
01:14:543 (100) - Honestly, a k here just sounds nicer, not sure why
01:38:353 (137,138,139) - k d k seems to flow better
01:49:782 (156,157) - k k has a nicer flow
01:59:782 (170) - Making this a d makes it less repetitive and it goes alright with the song
02:09:782 (181) - For the same reason I think this should be a k
02:13:591 (185) - ^^^^^^^^^^^^^^^^^^
02:16:448 (188) - ^^^^^^^^^^^^^^^^^^
02:20:258 (194) - This is just an opinion, the slider is fine, but making it repeat like that does nothing to the slider in the map itself. Personally I'd have fun making some stupid shape or something just to see if people notice LOL
02:23:115 (195,196,197,198,199) - k d k d k flows really well with this
02:27:877 (201) - k for consistency assuming you did the other stuff
02:35:496 (210) - k follows the pattern better
02:42:162 (221) - k sounds less repetitive and fits with the flow
02:48:829 (230) - k for consistency with what you were doing before I came along and fucked up your entire Kantan :v