When Sawada Tsunayoshi woke up, two hours after whatever his father and his father's boss did to him, he held a different set of memories in addition to his current one. This changes everything yet nothing at all.

Eventually, history repeats. 'Right,' Yu thought. 'Tousan and Papa are never allowed to hear about this.' Part of the Adoption by Kidnapping Verse

"I think," Tsuna said gently, "that it's time you told me what exactly that Mask Program did to you." Part of the Adoption by Kidnapping Verse

Possession is 9/10ths of the law. Or what else did Tsuna expect Yu to learn when Tsuna's own Guardians, husband and friends ran around kidnapping Yu and his friends for "training". "Dibs," Kyoya said. "Kyoya you can't call dibs," Tsuna said, half scandalized and clearly beginning to panic. "How do you even know what dibs is!" Part of Adoption by Kidnapping verse

Really, this entire thing was all Tsuna's fault. It was his pet project after all. Eventually Tsuna was doomed to find a child he had to bring home. Part of the Adoption by Kidnapping verse

To say Tsuna was worried sick out of his mind was like saying the sun was bright, the sky was blue. A glorious understatement that didn't even begin to cover what he was feeling. Someone had taken /his kids/. There was hell to be paid. Part of the Adoption by Kidnapping Verse

"I have a tutor." Sniper looked up at his companion. Sawada Tsunayoshi was, by all appearances, someone he had never expected to last long here. But the teenager had proven to be quick on his feet, full of grim determination despite his gentle heart and soft smiles. "Is that so?" Sniper said, out of mild curiosity. "Yes."

no one ever seemed to understand, you do not get between a Sky and their Elements. Sequel to Adoption by Kidnapping

In which Tsuna frets, Reborn is amused and their little sniper manages to inherit some of his fathers' more troublesome habits. Sniper-Mask-is-Reborn-and-Tsuna's-kid!AU (Do not need to know Tenkuu Shinpan in order to read this)