Honestly speaking, I wasn't sure which one was the band's name and which one was the song's title. But thanks to J-Wiki, I was able to figure it out.
I Don't Like Mondays. is a stylish rock band that's been around since 2012 and consists of four members: vocalist Yu, guitarist Choji, bassist Kenji and drummer Shuki. Their abbreviated nickname bandied about among the fans is IDoLa (アイドラ...based on the pronunciation of the name) and in terms of writing, they can also be identified by IDLMs. According to their Wikipedia article, the unusual name for the band originated from the fact that the members had wanted a whole sentence as the name, and apparently they really don't like Mondays. Mind you, I'm pretty sure that a lot of the working class in my nation have no love for Mondays either.
IDLMs may be categorized as a rock band but their September 2020 single "MR.CLEVER" definitely sounds more like R&B, perhaps in the hip-pop zone. Words and music are by the band and though "MR.CLEVER" is pretty short at around 3 1/2 minutes (ah, but longer below), the bopping melody and Yu's nimble dance with the lyrics make it all worth it.
Also reading that the guys are into the fashion industry and make their own music videos, the band does look really slick in the video for "MR.CLEVER". Only a few days ago, I was referencing the 1998 film "Ronin" in another article, one of the best flicks involving a MacGuffin, and the video has the guys involved in a bit of their own espionage derring-do with a mystery package which is passed along among a network of underground Tokyo types. There's also some "Reservoir Dogs" and maybe even a bit of "Ocean's Eleven" as the video ends on a touch of humour. Mr. Clever was obviously a little too much of his name for his own good.