Sorry for double-posting. No idea how the eff to quote multiple times with this new forum layout. :/
Eh, I've sorta given up on trying to decipher these passwords. The uploader even says the password should be obvious...but unfortunately, these content creators are xenophobic as usual, so we're probably not going to be getting a positive resolution unless you know someone well versed in Japanese and/or Japanese culture.
FWIW, 大らかな心でもってパス探しをして下さいwww まぁ (the hint): "Please search for a path with a big heart www"
I assume the "www" means online/on the internet.
The problem with this is that "大らかな心" can be translated a number of ways: a great heart, a great mind, a MATURE person...and so you can sort of see how, even if you're unfamiliar with Japanese idioms, that may turn into something entirely different (aka dirty), and Googling doesn't really do much here. Therefore, to non-native Japanese, the answer is not at all obvious, which is the point of the password.
Sorry I couldn't be of much help, but I'm ignoring these sorts of things. Honestly, having no collaboration or communication with these content creators, and what they're trying to do in isolating themselves, is counter-productive. They can share with themselves all they want in terms of content, but eventually, they're going to flame out or get bored, and English-speaking mugen creators either can't or won't help them due to the Japanese being so xenophobic and selfish.