I enjoyed this manga a lot, however it's not completely accurate. Alters cannot disappear, they cannot vanish. Alters can go dormant, sort of like a long sleep, and alters can intagrate. Intagrating is like combining colors one alter is red and one alter is blue, after intagration they are purple. Equal parts both blue and red but also now their own individual as purple.
Also there is no "true" alter or "original" alter. Having DID is like if you break a plate. All the alters are all pieces of the broken plate. They are all part of the plate, this includes the host. The host is also an alter and also a piece of the plate.
Parts I did really enjoy were:
Positive switches: like the strawberry shake causing a switch.
Innerworld: the inside of the mind where the alters can all meet and interact
And most importantly to me the fact that for the most part all the alters were treated as their own individual. They were treated as their own person as they should be.
Thank God she was honest I don't know if I could have taken it if she played it off and we had 30 more chapters of him not knowing