The Cheating Lab -Ten Experiments to Keep Her Unhurt and Your Conscience Clear-

The protagonist found himself confessed to by his classmate Sakura.
Though overjoyed with his first girlfriend, his childhood friend Toka – who he’d grown distant from – suddenly invited him over after so long.
Toka explains that Sakura had confided in her, worried her boyfriend might cheat. With piercing eyes, she poses the question:
“Tell me… can you really promise you’d never cheat?”
Though he insists “Never!”, he grows uneasy realizing he can’t even define what counts as cheating. Seeing his turmoil, Toka offers an unexpected solution:
“Why not test the boundaries yourself and decide? If an act feels like cheating to you, then we stop. Simple, right?”
And so, at his childhood friend’s insistence, their forbidden “lab experiments” begin…​