Omorai-kun is a simple gag manga, with the focus here being that Omorai, the main character, is a beggar and is covered with dirt. This is apparently hilarious, because Omorai’s layer of dirt results in: everyone avoiding him, him getting people sick when they accidentally touch him, him eating his dirt, him making a flute out of his dirty, his dirt turning everything it touches black etc.

These jokes make up roughly 85% of the manga, with the remaining 15% involving jokes about dandruff, snot, farting and so on. If that sounds like your type of humour, go ahead and read Omorai-kun, but, personally, I found the jokes too childish and boring to be entertaining (though I’ll admit that I’ve not seen jokes about dandruff before in manga so points for creativity?)

Otherwise, the art’s also rather simplistic and poor quality, with the cast of characters not adding much either. The main two characters, after Omorai, are his 70 year old friend - a fellow beggar and Omorai’s ‘trainer’ in begging - and Okomo - a young woman, also a beggar, who the mangaka uses as unnecessary fanservice (though the fanservice is nowhere near as sexualised as ecchi is today). There’s no development, or even proper personality, in any of the characters of Omorai-kun; seeing as this manga is a ‘comedy’, this wouldn’t be a problem had Omorai-kun actually been funny - which it wasn’t.

So, TDLR; not funny didn’t laugh

(Side note: you could argue that there’s a strong sense of discrimination/mockery against beggars, in Omorai-kun. Examples of this include jokes that the homeless: swim in sewers, eat tamagoyaki made of shit, and so on. That said, this was written 50 years ago so, to quote the ebook’s afternote: “works like this are not created with the intention to promote discrimination… take into account the historical background and time of release”)