JR East Pass and reservations?

Hi there,

Yes, it does - but not the Shinkansen between Tokyo station and Yokohama, as this is operated by JR Central.

Having said that, you are perfectly fine using a ltd. express or normal train between Tokyo/Yokohama.

If you go to Sendai, then you would likely use a normal train to Tokyo station and then the Tohoku Shinkansen to Sendai.

Kind regards,
Daniel