This is fun. Like that youngster peering around the seat. Really like the perspective too. Train rides are quite enjoyable. I went to Japan in 2008 and our group rode the bullet train from Kyoto to Tokyo. Very comfortable ride. Congrats on the DD!
As a whole, this drawing is extremely good, with an excellent finish. Your art (at least what I've seen of it), is DEFINTELY anime or manga-worthy, no doubt about that.
For the small details : I really liked the little guy eyeing the red fish, and the background isn't anything to worry about, because in a fast moving train, the background always blurs in a still.
Last of all : Congrats on the DD ! You really deserve it.
Aww the kid wants to pet the fishy~