Comparison between Ubu, Toku, and Kiwame states.
In Touken Ranbu, newly-obtained swords are always Level 1 and have preset stats that are unique to each sword. These swords are in their Ubu (初) form, i.e. the original form a sword starts out with.
In order to increase their stats, the player can refine their swords or send them to Internal Affairs to raise stats to a maximum cap. To increase stats beyond this maximum cap, however, swords can be further upgraded by leveling them up, or by achieving certain requirements.
Toku (特)
Toku (特) is an upgraded state that is reached once an Ubu sword reaches either Level 20 or 25, depending on the sword. It happens automatically after the sword levels up. The upgrade fully restores the sword's HP, while also permanently boosting its stats.
Kiwame (極)
Kiwame (極) is the further upgraded state that may be achieved through further training of a sword which has satisfied the requirements set.