Kiss the Widow, Escape the Funeral

Quick answer: 9 episodes, English original audio, and episodes 1–9 play right here tonight.

Kyle, an ordinary man, and a group of guests receive strange invitations and are pulled into a cursed manor. They are forced to take part in a deadly black funeral. They must follow the entire ritual; anyone who breaks the iron rules will be erased. In a moment of crisis, Kyle awakens the Love Plunder System. To survive, he has to max out the favorability of Vivian, the powerful widow of the deceased. Desperate to stay alive, Kyle grows intimate with Vivian little by little at her husband’s funeral to gain her favor.

He faces threats from her mutated, monstrous late husband as well as the curse’s rules. With his insight ability, clever exploitation of rule loopholes, and secret help from Vivian, Kyle overcomes danger after danger. In the end, Kyle teams up with Vivian to defeat the monstrous husband, breaking free from the cursed manor and returning to the real world. Fate shatters the undead shackles. Kyle and Vivian reunite in reality and live happily together.