21st Century Ninja

Two ninja "ki" adepts, Nobuo Yasuda and Shinobu Hayashi, are brought together by their families and get married. Psychically and sexually compatible, their "ki" powers grow stronger each time they bond physically.
Their enhanced "ki" abilities enable them to assist the secret women's ninja society that their mothers belong to. Together with the Society, they go up against plots to infect the Japanese with biological and chemical weapons.
An interesting read for Adults interested in ninja fiction.