Happy Kanako's Killer Life is a 4 koma comedic manga about Kanako's whimsical life. But it's really not funny. I guess the appeal is that gap between Kanako's pushover-type personality and her plain appearances against her actual job occupation as a assassin for hire is funny? I don't get it. It's kind of the same exact template each chapter, and the comedy gets extremely stale, since it's the same thing over and over again. Kanako gets annoyed by somebody, tries to kill them or suppresses her urge to, and if the author is feeling a little dangerous, he'll also sprinkle in Kanako being on a social scenario, making her extremely anxious. Like I get it, haha, Kanako can't make friends or conversations, but she's an extremely talented killer. It could be funny for five chapters or something.
There's some characters that kind of matter in the story, like Kanako's boss, her coworkers, and maybe even a couple of friends or even love interests, but they're kind if just there to fill the role rather than having an actual personality that gets dug into.
I give credit when credit is due though: the art is very nice. It's one of the best looking 4-koma manga I have ever read. The art is clean, the backgrounds nice, facial expressions vibrant. It's colored, and not like the crappy manwha webtoons either. The animals drawn in with Kanako's puns are a nice addition.
But alas, art does not carry a comedic manga very far if I don't think it's funny.