I have a lot to say about korosuke as a character too, specifically in comparison to other robot characters in media. Doraemon for example, a character made by the same creators, is a robot cat and they make that very apparent. It's core to his character, there's several episodes focusing on it like when he breaks down and needs to get fixed, and it's also important to his backstory too- he got messed up in factory assembly and has a loose screw, which is why he isn't exactly the best at his job of being a caretaker robot. I've always thought that when you have a robot character it is most interesting to explore those aspects of the character, like how being a robot changes their way of life and problems that arise from that and whatnot. But oddly enough, Kiteretsu kind of does the opposite.
Korosuke is a robot made out of random household objects that kiteretsu (the character) made using blueprints left by his ancestor. But in terms of how he is as a character, he's literally just a toddler. He's 2 years old in the birthday episode and always acts like a typical preschooler would, playing and watching cartoons and drawing with crayons and crying over stupid stuff and reading hiragana-only books because he can't read katakana or kanji yet. And funnily enough, him being a robot is only ever occasionally addressed... For the most part, everyone in the show treats him like any other typical preschooler. There's only a handful of times where korosuke being a robot is a factor in the episodes- there was one where he briefly got extremely sick (from one of kiteretsu's inventions that intentionally causes illness) and his mom was panicking because she realized she couldn't exactly call an ambulance for him since he "doesn't have a human body". Another episode had Korosuke find that he has bad eyesight and has to wear glasses (which he found embarrassing lol), but kiteretsu looked into it and realized he just had a loose screw in his eyes and it quickly got fixed. Aside from small bits like that, there is barely anything that differentiates him from a human outside of appearance- he has bodily needs and feels pain and emotion and the whole nine yards.
However, he is still well aware of what he is, the fact that he isn't human. There was one episode I had watched where korosuke got disqualified from an eating contest because he was a robot, and when the judges saying things like "wait, you're a robot? Really?" Korosuke just says "yeah but I thought everyone knew that". Most of the time it doesn't seem to bother him (though there was one episode where he wanted kiteretsu to upgrade him into being a cooler stronger robot), but there are a few episodes that address one of the problems with being a robot, which is essentially being immortal.
Korosuke can't physically or even mentally age, and he is aware of that fact. He knows he is going to stay a child forever while all of his friends and family will one day grow up and become adults. There is an episode where the characters are talking about the concept of being a homestay, and one of the characters says something like "oh so it's basically just going to someone's house and not doing anything except eating all their food. Wait, isn't that kind of what Korosuke does?" And it hits him really hard... Kiteretsu and their parents jump to Korosuke's defense and say he's a valued member of the family, but Korosuke still feels awful about it, feeling like he's just a freeloader. Kiteretsu tries to comfort him by saying that that's just how all little kids are like, but Korosuke retorts "but I'm always going to be a little kid!" The rest of the episode is about him running away from home and eventually realizing his family loves him and doesn't think of him as a burden in a cute and sappy way. There was another episode tackling this same subject that I already talked about in another post, but one thing I forgot to mention is that there's a line Korosuke says that's like "they don't understand what it's like to be stuck as a kid forever". The ending of that episode also showed that even after 20 years, Korosuke does in fact stay the same both physically and mentally, but he still lives with Kiteretsu (who is now an adult) who still loves and cares about him like family even then.
The more I think about it, the more of a sad thought it is, but also oddly sweet. The show insists over and over again that no matter what happens, they'll still always love Korosuke. It handles such a thing with a surprising amount of sincerity for a wacky 90s anime... Doraemon in both the original anime and the modern one has a few sappy episodes like that, it's hard to really compare but it gives me similar vibes, though I think kiteretsu is a bit more sincere in a way. As someone who has known what it's like to be unable to be independent because of factors outside of your control, the whole thing resonates with me in that sense... Even if someone will have to take care of you forever it doesn't mean you're a nuisance for it, you know? I don't think it's meant to be THAT deep, just a comforting fun show, but it's very heartwarming.
