Answer: Taoism
Explanation: Taoism is China's only true indigenous religion. It is based on the principle of Ying and Yang (Heaven and Earth) which believes the Man and Woman are representatives of Heaven and Earth.
Taoism advocates sexual practices and techniques for conservation of sexual energy.
Ying being the male sex has the Qi (life force) which is believed to decrease with ejaculation and cause premature ageing amongst other things, while Yang the female sex, has the Jing (Essence) which is rich and doesn't depreciate or diminish since the woman doesn't ejaculate from the act like the male. The Taoist sexual techniques therefore is believed to help the male absorb Jing from the Ying (Woman) to increase his own Qi. This is believed to help increase vitality, improve ageing, long life and spirituality.