Both .JP and .CO.JP domains have additional requirements. For most .JP domains, the domain owner must have a contact address and telephone from Japan.
The problem with .CO.JP domains is the fact that in order to register a .CO.JP domain, the domain owner must be a company incorporated in Japan (each company can request a single domain). This is why it’s kind of difficult to find a way to register .CO.JP domains if you do not fulfill the said requirement.
However, there is another option - Trustee services. These are somewhat costly, but they are your only option unless you have a registered company in Japan. Nominus (the registrar I linked above) offers this service. The same goes for other .JP domains
That all said, nothing inspires more trust in Japanese companies and customers than a .CO.JP web address, from Cape Soya to Nagasaki. A .co.jp address, which is reserved solely for firms registered with the Japanese government, communicates to the rest of the world that your company is genuine and trustworthy. Non-Japanese companies that are registered as Gaikoku Kaisha (Foreign Company) in Japan are also eligible to register .co.jp domains.
You may use your .CO.JP domain to:
- Establish and expand your company's influence in Japan.
- Protect your trademarked name by preventing others from using it
- Instill trust in Japanese customers by using a well-known web address.
- Make your website appealing to Japanese businesses and customers.
- Boost your chances of succeeding in Japan.
If you need a recommendation for a domain registrar, then I can safely recommend Nominus and their JP Domains.