Been a while since we covered Northgate, specifically the main drag (in fact, at of the time this was originally posted, from Chimy's we've covered from Wellborn to this bar, except for Duddley's Draw). 315 University is believed to have been built in the late 1940s, and trying to find the backstory of the building has been a bit difficult. The earliest I can find is 1971, when it was the original home of Budget Tapes & Records (a local store, not the chain as the University Square article, as of this writing, purports). In March 1981 the store moved out and while the owner tried to open an arcade in the spot, no information has been uncovered. In 1986, it became a restaurant known as Wing Joint, which was later bought and incorporated into the space of Cow Hop next door. In 1993, it too closed and moved out to University Square, leaving the combined space to a large bar called The Bullseye, which by 1995 closed and became two bars: "The Alley" (315) and "King of the Roadhouse" (317).
The Alley would soon give way to Coupe De Ville, which was sued in 1999 after a recently-turned 21 year old slammed a number of potent drinks between midnight (when he could legally buy alcohol) and 2 am when the bars closed. (Police found him dead with a blood alcohol content of .48, a lethal amount and four times the legal limit). Unfortunately I can't find the original articles in question (especially the Houston Press article which described some of the drinks and their contents...what do you expect from drinks like "DWI" or "Liquid Cocaine"?) but Coupe De Ville got sued and ended up selling out. In 2005 it became Bar 315, which closed in March 2012 and it remained empty up until Whisper Sister Shots opened in May 2017 after over five years of vacancy. Bar 315 did change the building facade significantly including removing the old awning and adding white brick to the outside, which Whisper Sisters continues to maintain.
UPDATE 09-17-2021: Deleted some redundant parts that were the result of carried over from an old post.