Following what it is said on the book of fourth edition, rank 1 kakita bushi "The way of the crane":
You gain a bonus of +1k1 plus your School Rank to the total of all attack and Focus rolls while assuming the Center Stance.
Does this mean that it gets a +1k1 to only hit, or to hit and damage rolls?
This is a tricky thing Let's go step by step!
+1k1 Attack Rolls and Focus Rolls, as well as in rounds after exiting Center Stance.
The rules are in the L5R Core Rules on page 82 (emphasis mine):
Attack & Defense
Any attack a character makes against an opponent requires a roll, typically a Skill Roll that includes a Weapon Skill as one of its components. Attacks may be melee or ranged in nature, depending upon the weapon being used. These rolls are made using the rules included for Skill Rolls above, and the result of an attack roll is compared to the opponent’s Armor TN. [...] If the result of the attack roll meets or exceeds the target’s Armor TN, then the attack was successful and the opponent was struck with the weapon in question. Damage must now be rolled.
Penalties or bonuses may be applied to attack rolls for a variety of reasons. [...]
Wounds
[...] The Wounds inflicted by an attack fill up these Wound Ranks in order[...]
Focus rolls only happen during Iaijutsu duels as step 2 after the assessment roll.
With Way of the Crane, you get +10 Initiative for that round and +1k1+Void Ring on any one roll (standard) and +1k1 on all attack rolls (Way of the Crane).
Attacks are an action that first demands a successful attack roll which then demands to roll for damage, a distinct and separate roll, that does not apply the same modifiers. You don't apply Way of the Crane on rolls for damage, but you could apply the standard bonus from Center Stance to a damage roll - provided you hit.
