expression, suru verb (irregular)
devote oneself to; make a job of; do exclusively
Used when someone concentrates on a single activity or makes it their main pursuit. Often followed by a noun or noun phrase indicating the activity.
彼は研究を事としている。
He devotes himself to research.
彼女はボランティア活動を事とし
She makes volunteer work her main occupation.
expression, suru verb (irregular)
decide to; make it a rule to
Equivalent to 事にする (ことにする). Usually written in kana. Indicates a personal decision or resolution.
See also: 事にする
毎朝ジョギングをこととしている。
I've decided to go jogging every morning.
彼はタバコをやめることとした。
He decided to quit smoking.