Relaxed bars for 40yos in Shinjuku

I'm at a bit of a loss here. Wifey and I (both 40) are in Shinjuku for a few days. We want to go to a bar before bed, but we're both pooped from a big day and most bars around here seem to be a bit more hectic than what we're after right now. We've sussed the hotel bar, but it's about to close.

Any recs for nice/quietish/cozy cocktail bars around kabukicho?

Thanks in advance.