Technique points are exclusive to the mist's seven swordsmen from GNW treasure. Sometimes you need them to use mystery (Jinpachi, Kushimaru, Ameyuri, Zabuza). In Jinin's case you c*e mystery without a technique points I think, but his technique points buff his ninjutsu and attack. Those technique points are consumed when you use mystery, so you need to regain them somehow. Some of those ninja will regain points when using standard or chase, some can't regain points on their own and you will need Mangetsu to give them technique points.