Really hoping someone mods in A culture with a Japanese samurai aesthetic. Here's one possible interpretation:
The culture could focus on melee and bows, with units able to fight longer due to reduced morale penalties and strengthened resolve from taking casualties.
Units
T1 Polearm - Ashigaru Footmen - standard polearm unit
T1 Support - Miko - healer
T1 Battlemage - Onmyouji - battlemage with spirit animal shikigami companion
T2 Polearm - Sohei - better polearm unit with warcry ability that applies i stack of strengthened and +5 morale on friendly units in a one hex radius and demoralizes adjacent enemies.
T2 Skirmisher - Shinobi - stealth unit with good evasion, a smoke bomb ability that grants hidden/invisibility for two turns, ability to place caltrops, and a ranged firebomb attack
T3 Shock+Ranged - Samurai - mounted shock unit with repeating ranged attack
All units have Way of Bushido trait, which grants a stack of strengthened the first time a unit takes damage each turn and halves morale penalties from casualties (if unit has multiple models)
Buildings
Kami Shrine - replaces T1 magic building , +5 mana income +5 draft income
Hachimangu - replaces Mana Obelisk - +10 mana +5 draft income
Onsen - replaces bathhouse. +30 stability +1 draft per population
Town Hall II: Yagura
Town Hall III: Tenshu
Town Hall IV: Daitenshu
Unique - Grand Dojo - +20 draft +2 ranks to all melee and physical ranged units built in this city

Bushido Culture Tome
Initial bonus:
Hero Skill - Way of Bushido - grants a modified Way of Bushido trait to the leader/hero unit (still grants strengthened when hit for the first time each round, but reduces all morale penalties by half, as heroes are single units and cannot take casualties)
Hero Skill - Weapons Mastery - hero gains +3 physical damage when using a melee or physical ranged weapon
Hero Skill - Mounted Combat Training - hero can use all weapons while mounted (enables mount slot for all weapons)
Unique Province Improvement - Samurai Estates - counts as farm, +10 food +5 draft, -2 food per war, +5 draft per war
Research
Honor From Death - buff spell - friendly units in a 1-hex radius gain tenacious for 3 turns, +5 morale, and +1 strengthened but lose 1 defense per unit tier
Bushido Code - Unit enchant - grants Way of Bushido to all non-culture units
???