honyaki ha asita hazimaru.

It is usually read ほんやき.

In this sentence, 本焼き is a noun. In contexts like pottery or ceramics, it often refers to the main firing or final firing. So grammatically, it is the thing being talked about, and the verb 始まる tells you what happens with it.

は marks the topic of the sentence.

So 本焼きは明日始まる is something like:

• As for the main firing, it starts tomorrow
• The main firing starts tomorrow

The important nuance is that は sets up 本焼き as the thing the speaker is talking about. It can also suggest contrast depending on context, but here it most naturally just marks the topic.

Because 明日 is a time expression, and very common time words often appear without a particle.

So 明日始まる is completely natural.

With many time expressions, Japanese often does this:

• 今日行く
• 明日始まる
• 来週会う

A learner may expect に, but with words like 今日, 明日, and 昨日, に is normally omitted.

This is a very common question because 始まる and 始める are a pair.

• 始まる = to begin / to start on its own
  
  • intransitive
• 始める = to start something
  
  • transitive

Here, 本焼き is treated as the event that begins:

• 本焼きは明日始まる

If you used 始める, you would usually need someone to do the starting, and 本焼き would take を:

• 私たちは明日本焼きを始める

That would mean we will start the main firing tomorrow.

So the given sentence focuses on the event itself beginning, not on the person who starts it.

Formally, 始まる is in the non-past form. In Japanese, the non-past can express:

• present
• habitual action
• future

Here, because of 明日, the meaning is clearly future:

• starts tomorrow
• will start tomorrow

This is very normal in Japanese. Scheduled or expected future events are often expressed with the plain non-past form.

A simple breakdown is:

• 本焼き = topic noun
• は = topic marker
• 明日 = time expression
• 始まる = verb

So the pattern is basically:

Topic + time + verb

Japanese verbs usually come at the end of the sentence, which is one of the biggest word-order differences from English.

Yes, you could, but the nuance changes.

• 本焼きは明日始まる

  • 本焼き is the topic
  • sounds like you are talking about it as an already established item

• 本焼きが明日始まる

  • 本焼き is marked more as the subject
  • can sound more like new information, or like you are identifying what is starting

Very roughly:

• は = as for X
• が = X is the one that...

In many situations both are possible, but they are not exactly interchangeable.

Yes. Japanese often leaves out information that English would state explicitly.

This sentence does not say who arranged the firing or who is responsible for it. It simply states that the event begins tomorrow.

In English, learners may expect something like:

• The kiln team starts the firing tomorrow
• We will begin the firing tomorrow

But Japanese often does not mention the doer if it is obvious, unimportant, or not the focus.

It is in the plain form, so it is less polite than 始まります.

• 本焼きは明日始まる。 = plain style
• 本焼きは明日始まります。 = polite style

The plain form is common in:

• casual speech
• notes
• schedules
• internal announcements
• neutral written descriptions

So it is not necessarily rude. It just depends on context.

Those spaces are usually added only for learners.

Normal Japanese is typically written without spaces:

本焼きは明日始まる。

Japanese readers naturally recognize word boundaries from:

• kanji
• hiragana
• grammar patterns
• context

So the spaced version is a teaching aid, not standard writing.