Perfectionist Complex, by Luka

You can accept yourself as you are, even though you're not perfect.

Luka explains why (with English subtitles provided by the uploader) in this song, which also has an excellent backing arrangement and a simple style of movie (by yonoP, based on another's image), which is all it needs. Indeed, it works better this way than in any of the other forms we usually encounter, I think.

I have been unable to find a non-Japanese form of the composer's name, but – from the Hiragana characters – it looks like 'Yamikuro'...