kono uta wo kiku tabi ni, koukou no tomodati wo omoidasimasu.

〜たびに means every time... or whenever....

So:

• 聞くたびに = every time I listen to it / whenever I hear it

This pattern is used when something happens repeatedly each time another thing happens.

Examples:

• 行くたびに = every time I go
• 会うたびに = every time I meet
• そのたびに = each time / every time that happens

In this sentence, hearing the song repeatedly causes the speaker to remember their high school friends each time.

With 〜たびに, Japanese normally uses the dictionary form of the verb, not the past form.

So:

• 聞くたびに = every time I listen
• not usually 聞いたたびに

This is because 〜たびに describes a repeated situation in a general way, not one specific completed event.

A good way to think about it is:

• Verb dictionary form + たびに = whenever that action happens

Other examples:

• 読むたびに = every time I read
• 見るたびに = every time I see
• 行くたびに = every time I go

The に is part of the grammar pattern 〜たびに. You should learn it as one set expression.

It does not work quite like a normal location/time に by itself here. The whole pattern means:

• every time...
• whenever...

So it is better to memorize:

• Verb + たびに
• Noun + の + たびに

Examples:

• 会うたびに = every time we meet
• 旅行のたびに = every time I travel

Because there are two different verbs, and each verb has its own object.

The sentence has two parts:

1. この歌を聞くたびに

   • この歌 is the object of 聞く
   • so it takes を

2. 高校の友達を思い出します

   • 高校の友達 is the object of 思い出します
   • so it also takes を

So the structure is basically:

• [this song] を 聞く
• [my high school friends] を 思い出す

It is not one long clause with two objects for one verb. Each を belongs to a different verb.

Japanese non-past often covers:

• present
• future
• habitual/repeated actions

Here it is a habitual meaning:

• Every time I hear this song, I remember my high school friends.

So 思い出します does not mean only I will remember. It can mean I remember in a repeated, usual sense.

This is very common in Japanese:

• 朝、コーヒーを飲みます = I drink coffee in the morning
• 春になると花が咲きます = Flowers bloom when spring comes

思い出す means to remember, to recall, or to have something come back to mind.

It often has the nuance of something surfacing in your memory.

So in this sentence, it is not just a static fact like I remember them. It feels more like:

• they come to mind
• I am reminded of them
• I recall them

That makes 思い出す a very natural choice with something like hearing a song.

It can mean either a high school friend or high school friends, depending on context.

Japanese nouns usually do not have a built-in singular/plural distinction the way English nouns do.

So:

• 友達 can mean friend or friends
• 高校の友達 can mean my friend(s) from high school

In this sentence, English might naturally translate it as my high school friends, but Japanese itself does not force that number.

The particle の links nouns together.

Here:

• 高校 = high school
• 友達 = friend(s)
• 高校の友達 = high school friend(s) / friend(s) from high school

The の shows that 高校 describes 友達.

This pattern is extremely common:

• 日本の文化 = Japanese culture / the culture of Japan
• 学校の先生 = school teacher
• 子どもの本 = children’s book / book for children

Japanese often leaves out the subject when it is obvious from context.

So even though English may need I, Japanese does not have to say it.

This sentence naturally implies something like:

• 私はこの歌を聞くたびに、高校の友達を思い出します。

But saying 私は is unnecessary unless the speaker wants contrast or emphasis.

This omission is one of the most common features of natural Japanese.

この means this and must be followed by a noun.

So:

• この歌 = this song

The basic set is:

• この = this ... near me
• その = that ... near you / that one just mentioned
• あの = that ... over there / distant from both of us

Related forms:

• これ = this one
• それ = that one
• あれ = that one over there

You use この because it directly modifies 歌.

Yes. 聞く can mean:

• to hear
• to listen
• to ask

The correct meaning depends on context.

In this sentence, because the object is この歌 = this song, 聞く clearly means to listen to / hear.

If it meant ask, the object would usually be something like:

• 先生に聞く = ask the teacher

So context and particles help you tell the meaning.

No. Standard Japanese is usually written without spaces.

The natural written form is:

この歌を聞くたびに、高校の友達を思い出します。

Spaces are often added only in beginner materials to make the sentence easier to read.

Yes, and it is understandable, but the nuance is a little different.

• 〜たびに strongly emphasizes every single time
• 〜と can mean when or whenever, often as a general result

So:

• この歌を聞くたびに... = every time I hear this song...
• この歌を聞くと... = when I hear this song..., I remember...

Both are possible, but 〜たびに is especially good when you want to stress repetition.

Either can work, depending on the English style.

Japanese 聞く covers a range that overlaps with both English verbs.

In this sentence:

• every time I hear this song
• every time I listen to this song

Both are natural in English.

If the speaker intentionally plays the song, listen to may feel slightly stronger. If the song simply comes on and triggers the memory, hear may feel more natural.

Japanese does not force that distinction as sharply as English often does.