Saito

The resemblance to Izuku Midoriya is striking and clearly deliberate. Saito shared the same wide eyes, the same fluffy mess of hair with heavy shadow pooling in it, and a comparable build. The differences were narrow: black hair and black eyes rather than green, and no freckles.

His school uniform was standard for his institute, a light dress shirt with a tie under a dark blue blazer. He also turned up in a dark blue t-shirt reading "Sometimes Tuesday".

Very little of his temperament ever reached the page. What the people around him agreed on was his popularity, which appears to have been considerable across the school. A flashback to Himiko's past also catches him in a fight with somebody, though the series never explains what started it.

Saito and Himiko attended the same middle school, and she developed feelings for him early. She wanted to ask whether he would give her a little of his blood, but held back, certain he would refuse and write her off as a freak.

Then came the fight. Saito was left bruised and bleeding for reasons never disclosed, and the sight of him in that state spiked everything Himiko had been suppressing. Her Quirk took over: she went at Saito with a box cutter, drinking the blood she drew through a straw, weeping with joy at finally letting herself be what she was. A schoolmate reported that her face carried a look of ecstasy.

The story broke publicly soon after. Himiko ran from both the school and her home, and her life as a villain started there.