What is the character is that in first row, first column of the pink word bubble in the first frame? It doesn't look like hiragana/katakna/kanji.

That's し, written with a funky font.

I see, thanks!

Sheesh, this series has a way of giving us translators all sorts of grief. In case anyone else was wondering, 思っきし is apparently an informalization of 思いっきり (something like "firm resolution").

Also, that was 方 (kata) in Kaito's line, not 万 (10,000).

Ahh, sorry about that. It makes more sense now, thanks.

Wow thanks! Everything makes sense now! =)