Three youths were arrested in the murder of a Little Tokyo restaurant chef, police said. Detective Robert Suter said two 15-year-olds and a 16-year-old were arrested in the Pico-Aliso housing project in Boyle Heights. Suter said the three were booked at Juvenile Hall on suspicion of robbery and murder. Teruhisa Tokunaga, 37, of Monterey Park, a chef at the Aoi Restaurant, was driving home early Sunday when his car developed problems and he pulled off the freeway onto Mission Road near the project. Minutes later three teen-agers confronted and shot him. Suter said the assailants took Tokunaga's wallet, reportedly containing about $20.