Are you talking about height? Like tiny x big?
can be anything. height, size, personality(?)
Size wise only thing I can think of is Bongchon Bride. Seme is a whole UNIT.
Height wise Love So Pure? Though honestly I haven't read that one. I just know they have a MAJOR height difference.
RAINBOW CITY
"Sugar Dog Life" - they give off the big spoon, small spoon energy :D
any big spoon small spoon yaoi?