noun
scooter with under-seat helmet storage
Wasei-eigo term derived from 'helmet in'. Refers specifically to a scooter or motorcycle that has a storage compartment under the seat large enough to hold a helmet.
wasei-eigo (Japanese-coined English), from (hel)met in
See also: メット
メットインのスクーターは通勤に便利だ。
A scooter with under-seat helmet storage is convenient for commuting.
このバイクはメットインだから、ヘルメットを置く場所に困らない。
This motorcycle has a helmet compartment, so you don't have to worry about where to put your helmet.