Universal rule.
A Hatamoto may be assigned as a Yojimbo, meaning bodyguard, to one character (but not another Hatamoto or a Shinobi) in the army at the start of the game after deployment if he is in the same unit.
While in the same unit as this character and within 3" of each other, half of the hits (rounded up) from Ranged Attacks assigned to the chosen character are taken by the Hatamoto instead (the attacker still chooses how hits are distributed).
If the protected character does not have the Way of the Warrior rule, it loses the Front Rank rule as long as it is in base contact with the Hatamoto.
If the character the Hatamoto is assigned to protect is killed by an enemy, the Hatamoto will immediately commit Seppuku as per the Death before Dishonour special rule. This does not apply if the model killed itself (by a miscast, for example).