Omukae desu. (1999)

Blurb:
You’ve heard of people who can "see dead people." But what if you could see dead people and a guy in a giant bunny suit that is trying to get them to the other side?

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 Modoka seems to have the power to see lost souls, he’s recruited to help lighten the workload. But many of the dead are reluctant to leave this world, feeling they have not accomplished all that 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.

Source: www.anisearch.com/manga/3161