follow
扈 centers on the idea of accompanying or following someone, often in a subordinate or attendant role.
扈 combines 户 (door) with 邑 (settlement), but the historical reason for this combination is uncertain. It may have originally referred to a place name or a specific type of follower, but the exact development is unclear.
Picture a follower waiting outside the door (户) of a settlement (邑), ready to accompany their leader.
For コ, imagine a follower calling out 'Co!' to get the leader's attention before following them: Co -> コ.