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to be involved (in); to get involved (in); to concern oneself (with); to take part (in); to interfere (in)
to relate to (a matter); to pertain to; to concern; to have to do with
to (seriously) affect; to concern; to have a serious bearing (on)
to stick (to); to adhere (to); to be particular (about)
この事件には多くの人が係わっている。
Many people are involved in this incident.
地域の問題に積極的に係わるべきだ。
You should actively get involved in community issues.
彼は長年この研究に係わってきた。
He has been involved in this research for many years.