Our mc is a fat and lonely otaku, who wants to kill himself. Debusen puts this disgusting man up front, so you can laugh at him, and feel glad you are not him.
Maybe you'll empathize with him. He is fat and ugly, and feels worthless. But along the ride, he is also cute, in his own way. And he is a lot of fun, for a short while. At the end, even this lonely otaku can have some self-worth, and a "purpose" in life.
If you like the first two chapters, you will enjoy the rest. The end is a bit rushed, the manga deserved more love, but it's a spin-off. The author Shin Kibayashi is famous for Kindaichi, and other "detective" manga. Debusen is a hidden gem.