From CMX:

Madoka is a high school student who is recruited by Nabeshima ? the guy in the bunny suit ? to work for the GSG (Gokuraku So Gei, a transportation service to heaven). Nabeshima is just way too busy, and since Madoka seems to have the power to see lost souls, he's recruited to help lighten the workload. Madoka is given the job of transporting wandering souls to the afterlife ? on motorcycle! But many of the dead are reluctant to leave this world, feeling they haven't accomplished everything they should have in their lives. Madoka must assist the deceased in performing tasks that will help them finally feel closure and make them willing to leave everything behind for good.

Includes a side story called Sweet Medicine in vol. 4.