“Voluntarily” in Japanese
Short answer
Voluntarily in Japanese is “進んで” (susunde). Full meaning: voluntarily, willingly, of one's own free will.
Other ways to say “Voluntarily” in Japanese
自分から
jibunkara willingly, voluntarily, of one's own accord
勝手に
katteni arbitrarily, of its own accord, without asking, voluntarily, willfully, as one pleases, selfishly, by itself, automatically
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