More stuff I've been thinking about !! Regarding Toshi's mother. I don't think the two of them were insanely close. Not because there was any resentment there but much like Toshinori is now, his mother was a huge workaholic. She spent most of her time working and leaving Toshi on his own because Toshi was a 'good kid' who 'never complained'.
She often praised him like this but the relationship was still a little distant as a result. She also liked to tell him he looked so much like his dad, though he started wondering as he grew up if she meant that as a good thing given she often seemed sad when she said it.
None the less Toshi's "neglect" in his youth is the reason he's always been very self-sufficient. His childhood largely consisted of him looking after his mother, perhaps more than she looked after him. He would get up for school every morning and make breakfast for them both so his mum didn't have to stress about it and could focus on her work, and he would make dinner for them both when he came home from school of an afternoon for the same reason.
The office building his mother worked in was totally destroyed by during a villain attack. She was among the causalities. He's not sure he ever came out of the shock of it, but maybe this was also because of the 'distance' that had already been between them, so it turned out losing her wasn't some huge adjustment and he met nana pretty soon after that which helped a lot.
Regarding his dad, Toshinori doesn't know much about him other than that he was American. His mother didn't talk much about him but she told him he died before he was born. To be really honest Toshi always had a quiet fascination surrounding his dad and what little he knew about him. One of his earliest memories was when his mother stopped at a kiosk and he found a comic book from America on one of the stands.
A that time he could hardly even read it properly but he instantly he thought about his dad from America and asked his mother if he could he have it. She was in a rush and knew he barely ever asked for things so she just said yes and he was very happy. It kept him quiet for a few days and she ended up getting a new one every week on their daily commutes until he got older and would get them himself on his way to school.
So needless to say, Toshi had a lot of comic books as a kid and his fascination with his dad is what evolved into his fascination with America.
You could also say Toshi's thing with trying to befriend and care for almost everyone around him stemmed from being a bit of a lonely kid growing up. Despite how friendly and approachable Toshi has always been, he never really had that many, if any, close friendships as a kid.
In his later years, this has a bit more to do with keeping folks at a distance due to his life as a one for all user, but as a kid he was always considered a bit "weird" by other people and this wasn't just because of him being kind of "different" as the "quirkless" kid because it wasn't really too unusual back then not to have a quirk.
Instead, this was more due to things like his bubbly demeanor, flighty impulsivity, and honestly sometimes just seeming a bit out of touch / dreamy, and maybe even a little disorganize.
Never in a truly "negative" way as Toshinori was never classed as any kind of 'delinquent', oppositely he was often considered a 'good kid' despite these 'faults', but these were all traits that still made him seem a little off or "crazy" to people.
In fact, it can probably be said that Toshinori might actually have undiagnosed ADHD. His impulsivity, poor time management skills and struggle with any kind of 'paper work' has continued into his adult-hood and caused some struggles in his day-to-day behind the scenes as a hero.
Thanks to people like Sir Nighteye and even Naomasa, Toshi's been able to get away with being late/sloppy with the paper work, but he still doesn't manage his time the best and is still as "impulsive" as he's ever been.