to enter, go into, get into a place or a thing / to join a group or organization / to be contained (in), to be included (in) / to be a member of a group, set, category

arrival at a location / (archaic) the wearing of clothing / (archaic) a kimono / (archaic, possibly obsolete) in the area around Edo, short for 巾着切り (kinchaku kiri, “a cutpurse”)

room

room

everything

(colloquial) current boyfriend

(slang) Alternative form of 彼氏 (kareshi, “boyfriend”)

everyone, one and all

a research student (i.e. a visiting or non-matriculating graduate student) / a researcher

researcher