Applying to multiple Japanese language schools — will that cause problems with the COE / immigration?

Hello — my wife and I are trying to enroll together in a 2-year Japanese language course. We’ve researched a lot and two of our top choices right now are Yoshida Institute of Japanese Language and Japan Tokyo International School (JTIS), though we’re looking at other schools too.

Before we start applying, I want to know whether it’s safe/advisable to apply to multiple schools simultaneously to maximize the chance that both of us get accepted. My specific concerns:

• If multiple schools submit a COE application or request documents for the same two applicants, will Immigration (or the schools) reject or delay the COE process?
• Do schools care or get upset if you apply elsewhere at the same time?
• Is there any risk of complications later (visa interview, entry, or residency) if more than one school is involved?
• Bonus: any firsthand experience with Yoshida Institute or JTIS — how did you like them?

We’re looking for real experiences or practical tips (e.g., whether to accept the first COE and withdraw politely from others, whether to tell schools you’ve applied elsewhere, timing tips). Thanks in advance — really appreciate any help!