Ben and Shinji have a good relationship with each other, as Ben had no problem letting Shinji fight alongside him against Aizen, and Shinji then saved Ben from Tosen when the rogue Shinigami tried to stab him.
Shinji and Hiyori have a comically hostile relationship, often throwing insults at, or even attacking, one another. They have been at each other's throats for decades, even spanning back to when they were still part of the Gotei 13. This conflict often involves Shinji making funny faces at Hiyori and the latter kicking or punching him in the face, though usually she starts the fights. Despite this, he does seem to care about her safety.