Little John is a well known jazz bar/tiny club in the Yokohama scene, yet its erratic opening hours can make it tough to visit. It's a small rectangular room with about 15 seats and a back wall 'stage', another 6 or so seats at the back counter bar. There's live music often but not nightly so you can drop by for a drink after 7 most days. It also takes part in most of the local Yokohama-based jazz events/weekends based on the posters hung around the room.
Even after finally entering the joint for the first time (for a gig as part of the 2015 Yokohama Jazz Promenade) Little John remains a bit of a mystery. Master Furukawa-san is friendly and chatty, but not the actual owner. He didn't really share the whole story with me but from what I gathered the owner is kind of ill and doesn't come by much, leaving it in the hands of Furukawa-san. He assured me he's there daily at 7 but several times I've been by and they were closed..the story seems incomplete, I'll keep investigating.
Regardless, Little John has that dark, divey old school jazz bar feel to it that many customers will enjoy, a place to run into to escape from a cold rainy night. You can easily make a night of it in Yoshida-cho visiting Little John, Jazz Ad-lib, Rock Bar Sid and some of the other music bars along those back streets.