Their current employee count is 180 as per their mynavi recruitment page.
I've noticed that a lot of sites are still using their outdated employee count of 150 people. Some months back I tried updating their awful wikipedia article with the correct information but someone changed it back to the old number lol.
Anyway, it was 150 back in December of 2018 and was updated to 183 in April of this year meaning that they had a pretty big expansion in jut a few months.(in my years following the company the most they usually add in a full year is in the 10 range) At first I thought this was for Fire Emblem Three Houses which had already been delayed twice at that point. But that is not the case as Koei was did most of the development.
Looking more closely at the website most of the new employees are new graduates. According to their mynavi page 23 of the 30 employees are new graduates. This is a big jump in comparison to the new graduates they hired in 2018(11) and 2017(3). Also on their company profile one of their goals for the year was to promote youth employment, so they're really making it a mission to add younger employees.
Since their total employees went down from April(183) to july(180), I expect that number to end up in the 170s if they update their main company
profile employee count for the end of the year (which they usually do every december, but there have been some years where they haven't).