Iroha should be friends with Minori since they're both gluttons hiding a secret. Minori is secretly a glutton with sneak eating skills while Iroha crumbles when she doesn't follow her step by step procedures. Torao and Mamoru should also be friends who do everything they can to hide their girls' secrets.
I love it when I imagine pairs befriending other pairs from different works like imagining Shouko and Hitohito befriending Kaede and Riku.