Passive Ability details for Store TP IV  

From what I can tell, this is like having gear with Store TP +25, meaning:

A Level 70+ Samurai with Store TP IV using a Great Katana with a 450 Delay would get:

* 5.0 + [(450 - 180) * 6.5] / 270 = 11.5 TP (for any job with a similar weapon)

Base TP * (1 + StoreTP%)

* 11.5 TP * 1.25 = 14.375 rounded to 14.3 TP

All this mumbo-matho means you'll need Store TP +21 in gear to have a 6-hit to 100 setup. If it's possible, you could do a 5-hit setup with +48. However, unless I missed a key piece of gear, the highest you can get is +47 with food and a few +1 Hachiman pieces. However, with full Store TP merits (+10) this is rather easily attainable.

Have fun.