A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
Brotherhood Sensei:
Your maximum hand size is equal to 6 plus the number of Temples you control, to a maximum of 10.
The Remote Monastery of the Dragon, going second side:
You have +1 starting and maximum hand size.
What is the maximum potential hand size you can have when going second with Dragon while running Brotherhood Sensei?
Brotherhood Sensei:
The Remote Monastery of the Dragon, going second side:
What is the maximum potential hand size you can have when going second with Dragon while running Brotherhood Sensei?
Brotherhood Sensei sets your maximum hand size to 6. It then gives your maximum hand size a bonus equal to the number of Temples you control, to a maximum of 10. As described on p13 on the Comprehensive Rules, bonuses "to a maximum" are applied after other bonuses. So, if you are a Dragon player going second, with 4 (or more) temples in play, you would calculate your maximum hand size as 6 (basic) + 1 (Stronghold) = 7, then min(7 + 4 (your Temples), 10) = 10.
However, remember that other bonuses and penalties, without a "to a maximum/minimum" clause apply first. For example, if your opponent is a Scorpion, who has given you 3 House of Floating Petals Geisha Personalities, but you also have 6 Temples in play, the calculation is 6 (basic) + -1 (his Stronghold) + -3 (the Geisha) = 2, then min(2 + 6 (your Temples), 10) = 8.
Or, going the other way, if you're going second and have 2 Farmer's Markets, 2 Takujin and 3 Temples in play, your calculation goes 6 (basic) + 1 (Stronghold) + 2 (Markets) + 2 (Takujin) = 11, then min(11 + 3 (your Temples), 10) = 10.