What does the Enforce Administrative Integration casus belli cost?

prestige; the amount depends on the titles, claims and distance, worked out when you declare.

Casus belli · Subjugation

Enforce Administrative Integration

Enforce Administrative Integration is a casus belli in Crusader Kings III (subjugation). If the attacker wins: All of the defender's lands will be confiscated and returned to the …. If the defender wins: As the attacker … not the …, the defender will remain a Sōryō Vassal. Declaring it costs prestige. The war goal is worth 1% war score. Patch 1.20.0.3, from game/common/casus_belli_types/10_tgp_japan_wars.txt.

Quick answers (3)

What do you get for winning a Enforce Administrative Integration war in CK3?: All of the defender's lands will be confiscated and returned to the … (patch 1.20.0.3).
What happens on a white peace?: The defender will remain a Sōryō Vassal.
What does the Enforce Administrative Integration casus belli cost?: prestige; the amount depends on the titles, claims and distance, worked out when you declare.

How the war ends

Attacker wins

All of the defender's lands will be confiscated and returned to the ….

White peace

The defender will remain a Sōryō Vassal.

Defender wins

As the attacker … not the …, the defender will remain a Sōryō Vassal.

If the war becomes invalid

The … has ended: the defender is not Sōryō or left the Realm

Who can declare it

The game shows no text of its own for these conditions; the script is below.

Every subjugation war (the group's allowed_for_character) (13 lines of game script)

herders_and_tributary_constraints = yes
pam_personal_pacifism_offensive_war_ban_trigger = yes
tgp_dynastic_cycle_offensive_wars_ban_trigger = yes
tgp_war_ban_all_ministers_trigger = yes
OR = {
	NOT = {
		government_has_flag = government_is_theocracy
	}
	AND = {
		government_has_flag = government_is_theocracy
		has_variable = koh_subjugation_cb_allowed
	}
}

As written in game/common/casus_belli_groups/00_casus_belli_groups.txt.

Attacker (allowed_for_character) (5 lines of game script)

government_has_flag = government_is_japan_administrative
top_liege = {
	government_has_flag = government_is_japan_administrative
}
tgp_is_ceremonial_liege_trigger = no

As written in game/common/casus_belli_types/10_tgp_japan_wars.txt.

Defender (allowed_against_character) (6 lines of game script)

is_landed = yes
government_has_flag = government_is_japan_feudal
top_liege = scope:attacker.top_liege
NOT = {
	is_liege_or_above_of = scope:attacker
}

As written in game/common/casus_belli_types/10_tgp_japan_wars.txt.

Cost to declare

Costs prestige. The amount is worked out when you declare (by the titles targeted, claims, distance and more), so the script is shown as written:

Cost (7 lines of game script)

prestige = {
	add = {
		value = 100
		desc = CB_BASE_COST
	}
	multiply = common_cb_prestige_cost_multiplier
}

As written in game/common/casus_belli_types/10_tgp_japan_wars.txt.

Source: game/common/casus_belli_types/10_tgp_japan_wars.txt and the English localisation, Crusader Kings III 1.20.0.3. “The attacker”, “the defender” stand where the game names the character; “…” marks other words it fills in during play.