セーフティーボックスに預かってくれないか。

safety

box

at (place, time); in; on; during; to (direction, state); toward; into; for (purpose); because of (reason); for; with; by; from; as (i.e. in the role of); per; in; for; a (e.g. "once a month"); and; in addition to; if; although

to look after; to take care of; to keep; to hold on to; to keep in custody; to take charge of; to be entrusted with; to receive on deposit; to reserve (judgment); to leave undecided

indicates a question (sometimes rhetorical); or; whether or not; some- (e.g. something, someone); indicates doubt, uncertainty, etc.; emphatic prefix; suffix forming adjectives or adverbs; in that way