MC looks like he just graduated.
From elementary school.
He looks like he's 4 foot 10(about 145 cm) and mom looks like she's at least a foot taller. Of course there's artistic license to exaggerate a bit.
Honestly, if you're going to do shota just embrace it fully. Make him a boy genius like Doogie Howser MD. Have some women react a bit oddly at first before adjusting to his surprising level of maturity. Just my .02. Some people hate shota, but you're going to get that regardless of what you tell them the character's age is.
This is Danny Devito standing next to Arnold Schwarzenegger. Arnold is 6'2", Danny is 4'10" tall. If you're shorter than 4'10" and an adult, you're considered a "little person"(an extremely low percentage of people are in this category).
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Note that even at this height differential Danny still comes nearly level to Arnold's shoulders. Then look at the MC here standing next to his, uh, landlady. Is she, perhaps, related to Maria Sharapova?
Having said all that, the art looks nice. Looking forward to future updates.