The Witches of Adamas manga volume 1 features story and art by Yu Imai.

Satou Yukinari has a very strange medical condition: he expels diamonds. But like all fortunes, it comes with a price. These special gems are worth untold riches, but each one he spurts out cuts a year off his life span! As word spreads of his condition, a trio of beautiful seductress witches descends, starting in his hospital room. Yukinari must overcome sexy but deadly temptation if he wants to live, but boy these witches are persistent!