Does “immersion” even work in Japanese public schools?

My school is trying something like an “immersion-style” approach this year. They cycle through the same textbook five times, each round focusing on a different aspect of English. There’s no explicit grammar explanation. The idea is that students will just “pick it up naturally.”

In practice, it’s kind of a mess.

When students have to retell or produce language, the strongest ones can manage things like “A is B” or “A likes B.” A lot of them seem to think the only verb in English is a be-verb.

When I check their writing, it’s rough. They’re just sounding words out phonetically. I’ll get sentences like:

“Tina’s is aets tosikosisoda.”

“Cota isnt here. he’s has the fiver.”

I understand the theory behind immersion, but can it really work in a context where:

Students get limited exposure hours. There’s almost no need to use English outside class. And grammar is never made explicit.

It feels like we’re expecting natural acquisition without providing the conditions that make immersion successful (massive input, consistent exposure, communicative need). The strongest students obviously are learning the grammar at juku or something.

Has anyone seen this approach actually succeed in JHS? Or is some level of explicit grammar instruction still necessary in this context?

by AdUnfair558