It have 6 chapters and 1 volume i guess

the story was about an alien who integrate in human society.

the alien have same looks like human, like he was looks human but he was from another planet.

The alien doing it to do some research and to continue their off springs and doing special mission or what to gather info about human society.

each of them assigned to mission and called conductor or navigator(i forgot)

it have 6 chapters with different characters each

1. story one was about a young office worker who falls in love with his co-worker who tell him she was alien and gonna move to her aiship, leaving earth.

2. Story two was the alien girl who love music and fall in love with the boy from her highschool and the boy managed to make some cd-album and it got popular.

3. the alien was a guy where her wife already dead and he works at book store

4. the alien was a man, his daughter was alien, and they have neighbour whose are brother and sister(they also alien), 4 of them did not know they were alien on special mission and thought the others was "arranged brain washed human to pretend to be family" for them to works in human society.(it had 3 chapters i guess)

yeah thanks