Most people don't choose reincarnation. Reincarnation finds their way to them. Perhaps they did something great in their life. Or maybe truck-sama wasn't looking where it was going. But without fail, those who reincarnate are destined for something great. A new life where everything changes for the better. But... Reincarnation isn't always the greatest thing. Sometimes you just draw the short end of the stick. Di Tou just happens to have drawn the shortest stick. Pulled out of his life randomly. Taken by a crazy old eccentric man not as a disciple, but as a body double?! And a janitor body double no less?! Grasping a system to find... It's a JANITOR SYSTEM!? Truly, how unlucky can one get?
As for Di Tou, for the most part he was kind of passed along between the four. When Wang Ming Chen was doing something fun, on a spur of the moment she would sometimes drag Di Tou along to play. When that wasn't the case, he would garden with Wang Ming Liang, who had found that the plants that Di Tou touched would almost never wither and never die, often coming back from the brink of death as if by some strange miracle.
When Wang Ku Mang was in town, he would often bring Di Tou around to eat, and if he found that wasn't interesting, sometimes he would give Di Tou a few things to play with or carry around after he found out about Di Tou's great strength.