Ruggie is not a fan of Rook, who touches his tail in a vignette what trying to convince him to share secrets about Leona.
Rook seems to pet and tickle Ruggie until he concedes, with Ruggie finally sharing Leona’s weakness (that he is not fond of vegetables) after Rook threatens to look into Ruggie’s weaknesses instead.
Rook is Ruggie’s third birthday interviewer. Ruggie is less than pleased to have to welcome Rook to the school store during New Year. When Rook asks to see Ruggie’s technique for crushing grape seeds with his teeth Ruggie responds, “It’s nothing special, so you can just not look at me. Thanks,” but he is delighted when Rook offers to pay for his grapes.
Rook says, “(Ruggie) is a deeply pragmatic person, Ruggie. Such an efficient, economical, grounded beauty!”
Ruggie looks out for Epel during Vargas Camp, patiently teaching him how to fish. Epel seems to look up to Ruggie in similar way to how he looks up to Leona, fetching him blankets and doing his cleaning tasks during the event.
Rook says that Epel is often regaling him with stories of Ruggie.