A Love to Light the Afterlife

When an accident suddenly claims Chiaki's life, his best friend Sousuke is left to wallow in grief and regret. While on his way home, Sousuke walks over a railway crossing exactly on twilight and finds himself in the Afterlife, where he finds Chiaki's spirit. Determined to be reunited with and resurrect Chiaki, Sousuke makes a wager with the Afterlife ruler, Lord Nushi. Will he succeed? (Summary from futekiya)