[quote=RockFace]
So, Spirit:I've read multiple cases of people "sensing large amounts of spirit" or something similar. How does that work? So anyone with a kage can just be tracked down, no matter where they are?Recharging spirit: Just sleep/rest? Time spent relaxing?
[/quote]

Spirit sensing is common in most kages, but not to the same degrees. For example, Jin (Ishigo's kage) and Castiel (Arianna's kage) are extremely well sensors. While Jin can sense spirit due to his natural watchful nature, he can only sense small disturbances (meaning someone using/expending spirit) in an area of about.... three hundred feet? However, Castiel, who is a telepath, can sense spirits much farther away.

Most kages can sense at least like within a few rooms of the same building. On average, however, most people can intentionally "suppress" their spirit, or have their kage lay dormant so as to not be sensed, unless their is a kage that is actually adept at it. I wouldn't consider your character's kage as a sensor, so I would recommend giving him basic sensory abilities.

As for replenishing spirit, yes, you are correct. Rest/recovery. A good night's meal/sleep is the best way. Also, keep in mind that the more the physical body is damaged, the slower the spirit recharges.

Also, yes, you can increase total spirit by training or constantly pushing your limits, but remember that it is very possible to hit stasis (spiritual coma).