Before Shinichi became a high school detective legend, he and Ran share a quieter moment caught between childhood games and first love. A mahjong tournament brings them together on a summer festival night, where the tile-clicking rhythm of the game becomes a backdrop for unspoken feelings neither quite knows how to voice. The mystery isn't grand or dangerous, but intimate: two people trying to read each other like players reading a hand, each unsure if the other feels what they do. As the Tanabata festival lights glow around them, a simple game becomes complicated by proximity and the realization that some puzzles don't have logic solutions. The story drifts between competitive banter and stolen glances, between the comfort of knowing someone your whole life and the flutter of seeing them differently. What begins as nostalgia becomes a moment where their relationship shifts in ways neither will forget. For viewers seeking romance that breathes, that trusts silence and small gestures, this OVA captures the delicate space between friendship and something more.