kono keikaku ni ha sien ga hituyou desu.

Japanese often expresses need with the pattern:

A には B が 必要です

This literally means B is necessary for A.

So:

• この計画 = this plan
• には = for / as for
• 支援が = support is the thing being talked about
• 必要です = is necessary

That is why the sentence feels more like Support is necessary for this plan than a direct word-for-word version of This plan needs support.

には is actually two particles combined:

• に marks the target or thing something is necessary for
• は marks that whole phrase as the topic

So この計画には means something like:

• for this plan
• or as for this plan

This is a very common pattern with 必要.

Yes, you can leave it out:

• この計画に支援が必要です = support is necessary for this plan
• この計画には支援が必要です = as for this plan, support is necessary

With は, the sentence can sound a little more like:

• setting up the topic
• adding slight emphasis
• or implying contrast, such as this plan, at least, needs support

In many real sentences, には sounds very natural and common.

Because 必要 is not a normal transitive verb like English need.

In this sentence, 必要 means necessary, so the thing that is necessary is marked with が:

• 支援が必要です = support is necessary

A native English speaker may expect を because English says need support, but Japanese is using a different structure.

If you want a more verb-like expression, Japanese can also say:

• この計画は支援を必要としています

That is closer to This plan requires support.

必要 is usually treated as a na-adjective.

That means:

• by itself in a sentence: 必要です = is necessary
• before a noun: 必要な支援 = necessary support

So in your sentence, 必要です is the main predicate.

It also has some noun-like behavior, which is why learners sometimes find it a little unusual at first.

この is the word used when you directly modify a noun:

• この計画 = this plan

これ stands alone as this:

• これは計画です = this is a plan

So because plan is written right after it, you need この, not これ.

Even though it is written は, the particle is pronounced wa.

So:

• には sounds like niwa
• not niha

This happens specifically when は is used as the topic particle.

No. Standard Japanese is normally written without spaces:

この計画には支援が必要です。

Spaces are often added in beginner materials to make the parts easier to see.

です makes the sentence polite and neutral.

So:

• この計画には支援が必要です。 = polite
• この計画には支援が必要だ。 = plain/casual

The です version is safe in most formal or neutral situations.

Yes. 支援 often means support, especially in a practical, organized, or institutional sense.

Depending on context, it could refer to things like:

• financial support
• logistical support
• political support
• technical support

So the sentence does not tell you exactly what kind of support is needed—only that some kind of support is necessary for the plan.