Clearances are much reduced compared to previous Shinkansen lines, and thus the 400 series units are much narrower than previous Shinkansen trains. Seat pitch is also reduced, which should be a warning to larger Westerners venturing to Japan!
Styling wise, the 400 series is another to have an aircraft-style nose with a pointed nosecone, though lower than 0/100/200 Series. Originally they were painted a medium silver grey with a darker roof and area around the cab windows and underframe, but they have been recently repainted, with a higher area of dark bluish-grey on the underside, coming up almost to the side windows, and separated from the silver grey with a green stripe. The dark grey on the roof and around the cab windows is gone.
They were originally six car sets, but a seventh car was added to each to reflect increased popularity of these services.