[1][2] Takayama was baptized into the Catholic Church in 1564 when he was twelve, though he later became disenfranchised from his religion due to his actions as a samurai.

[3] In 1571, he fought in an important and successful battle as part of his coming-of-age ritual which culminated in a duel to the death with a compatriot whom he killed; however, Takayama received grievous wounds in the process and during his convalescence realized he had cared little about Catholicism.

[5] The colonial government of the Spanish Philippines offered to invade Japan and overthrow Tokugawa in order to protect Japanese Christians and place him in a position of great power and influence.

At Plaza Dilao in Paco, Manila, the last vestige of the old town where around 3000 Japanese immigrants lived after the expulsion, a statue of Takayama stands depicting him in the traditional samurai garb and a topknot.

The University of Santo Tomas also has a statue in honor of Takayama in front of the Thomas Aquinas Research Complex building.

His cause for sainthood started at a diocesan level which resulted in the validation of the process on 10 June 1994 after the Congregation for the Causes of Saints (CCS) were given all the boxes of documentation pertaining to the cause.

The first attempt came in 1630 when the Manila priests decided to commence it but this failed due to the isolationist Japanese policies which prevented the collection of the documentation that was needed; the petition was presented but was rejected.

His cause was to meant to confirm - in a rather unorthodox case - that Ukon was a martyr because of the treatment he received and because he renounced all he had to pursue and profess his faith.

The cardinals and bishop members of the CCS met on 18 June 2015 to make a final decision on the cause before it could go to Pope Francis for his approval, and they had to meet again on 12 January 2016.