Would a British honorary colonelcy qualify Yonai as army minister?

Could an honorary colonelcy from George VI let Yonai serve as his own army minister?

No. The qualification required an officer of the Japanese Army, so a British honorary colonelcy would not solve the problem.

A suggestion to give Yonai an honorary colonelcy runs into the nationality of the service required for the army portfolio. The minister must be an officer of the Japanese Army. A British honorary appointment from George VI would therefore leave the cabinet's army qualification unresolved.