Tenma is the second foal out of the unraced Amagansett (Tapit). Her first is the 3-year-old filly Hampton Yard (Uncle Mo).

Second dam Twirl (Galileo) won the Listed Hurry Harriet S., was twice second at Grade 3 level and has produced one winner.

Third dam Butterfly Cove (Storm Cat) never raced but produced six winners. They include the champion Misty For Me (Galileo), a multiple Group 1 winner and dam of the champion and sire U S Navy Flag, a dual Group 1 winner, of the dual Group 1 winner Roly Poly, the Group 3 winner Cover Song and the Listed winner Greenfinch. Another is the champion Ballydoyle (Galileo), winner of the Gr.1 Prix Marcel Boussac and placed in a Classic, whose foals include Red Riding Hood, winner of the Gr.3 Snow Fairy S., and the Listed winner Monday.

Amagansett has a yearling colt by Munnings.