KhemaKhema

In the past, it used to be: As the process involves a document called TM86 called "change type of visa, การเปลี่ยนประเภท" , and as the person in question does not hold a visa proper, it used to be not possible. However, you might contact your local immigration office and ask for advice. What is impossible in one province may be possible in another province. It is also possible, to apply for a Non-I type R visa from abroad, in your case from Japan. In any case, including applying from abroad, the person in question needs a supporting monastery in thailand to issue him all the usual documents involved with applying for a Non-I type R visa. This includes, a letter of recommendation from the department of religious affairs, an invitation letter from a monastery in thailand, a letter of support from that monastery and others.

If this is a temporary ordination (sometimes also called a traditional ordination), you should be fine with your existing visa. The duration of your existing visa must not end during your monkhood. Usually everyone in Thailand is very supportive to ordination, immigration is most likely to be supportive/acceptive/turn a blind eye. You should make your situation clear to your preceptor (Uppacayo) before ordination, go for a visit to his temple and have a friendly chat. Most strict forest monastery will not accept a married applicant, however, one may go forth as a novice in that case. Read all about it: https://www.dhammatalks.org/vinaya/bmc/Section0054.html You must have a written allowance both of -your wife and -your parents to become a monk. In case you are contemplating of staying on as a monk indefinitely, i would think twice. You will not be able to get a Non-I Visa type R(eligious studies) as a married foreigner.

This is the same place as: https://papaemeditation.org/thailand/ It is running for quite a number of years already. The place belongs to the Dhammakaya group.