A busty boy is intended to be a masculine character with substantial breast growth, regardless of their visible features. The presence of breasts usually results in such a character being treated as a female or gynomorph according to TWYS, but a busty boy may also include male (lore), andromorph (lore), or trans man (lore) among their lore tags.
While there are some real-world analogues for this, including symptoms like gynecomastia and moobs, busty boys are usually more fantastical or extreme; they often have the size and form of medium breasts or larger, and they may wear a bra.

See Also:

• gynomorph
• male_(lore)
• andromorph_(lore)
• maleherm_(lore)
• trans_(lore)
• trans_man_(lore)