Veil of Obsession (Tsunayoshi Sawada tyl X OC)

A decade after Tsuna's reluctant rise as Vongola's leader, a woman steps into his world-a fierce but enigmatic soul named Isabella, hiding a double life and secrets that could shake the very core of the mafia. Drawn to her strength and haunted by her darkness, Tsuna finds himself caught in a passion he cannot control, even as a shadow from her past threatens to destroy them both. Allies whisper of her hidden motives, and a man's schemes sending ripples through the criminal underworld, her loyalty is tested in ways that could either unite the Vongola or tear them apart forever.