He will join us later.
Kare wa ato kara kuru yo.
he; him; his; boyfriend
topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis
behind; rear; after; later; after one's death; remainder; the rest; descendant; successor; heir; past; previous; more (e.g. five more minutes); left
from (e.g. time, place, numerical quantity); since; from (originator); by; because; since; out of (constituent, part); through (e.g. window, vestibule); after; since
to come (spatially or temporally); to approach; to arrive; to come back; to do ... and come back; to come to be; to become; to get; to grow; to continue; to come from; to be caused by; to derive from; to come to (i.e. "when it comes to spinach ...")
indicates certainty, emphasis, contempt, request, etc.; used when calling out to someone; used to catch one's breath or get someone's attention; yo!