higaeri no ryokou nanoni, nimotu wo motisugite simatte, sukosi koukaisimasita.

日帰り means going and returning on the same day. In natural English, it often corresponds to a day trip.

So 日帰りの旅行 is literally something like a same-day trip or simply a day trip.

You will also see 日帰り in other expressions, such as:

• 日帰り温泉 = a hot spring trip with no overnight stay
• 日帰りで行く = go and come back the same day

The の connects 日帰り and 旅行, letting 日帰り modify 旅行.

So the structure is:

• 日帰り = day trip / same-day return
• の = links one noun to another
• 旅行 = trip

Together: 日帰りの旅行 = a day trip

A native English speaker may expect something more like a single compound noun, and in fact Japanese also allows that here.

Yes. 日帰り旅行 is also natural and very common.

Both are understandable:

• 日帰り旅行 = compact compound noun
• 日帰りの旅行 = slightly more explicit, with の linking the words

In this sentence, 日帰りの旅行なのに sounds perfectly natural. A learner should recognize both patterns.

Because the word before のに is a noun phrase.

With verbs and い-adjectives, you attach のに directly:

• 行くのに
• 高いのに

With nouns and な-adjectives, you usually need な before のに:

• 学生なのに
• 静かなのに

Here, 日帰りの旅行 is a noun phrase, so:

• 日帰りの旅行なのに = even though it was a day trip

なのに expresses contrast, often with a nuance of unexpectedness, disappointment, or despite that.

Here the idea is:

• It was only a day trip
• but despite that, I brought too much luggage

So なのに is not just neutral contrast like but. It often implies:

• even though
• despite the fact that
• and yet

That nuance fits this sentence well, because bringing too much luggage for a day trip feels unnecessary and regrettable.

It is made from several pieces:

• 持つ = to carry
• 持ちすぎる = to carry too much
• 持ちすぎてしまう = to end up carrying too much / carry too much and regret it
• 持ちすぎてしまって = the て-form, used to connect to the next clause

So the full structure is basically:

• 持つ
• → 持ちすぎる
• → 持ちすぎてしまう
• → 持ちすぎてしまって

This is a very common Japanese pattern:

• verb stem + すぎる = do too much
• てしまう = do completely / end up doing, often with regret

しまう often adds one of these nuances:

• completion
• doing something unintentionally
• regret / unfortunate result

In this sentence, the important nuance is regret or I ended up doing it and now I wish I hadn’t.

So compare:

• 荷物を持ちすぎて = carrying too much luggage
• 荷物を持ちすぎてしまって = ending up carrying too much luggage, unfortunately / regrettably

That fits well with the next part, 少し後悔しました.

The て-form connects this part to the next clause:

• 荷物を持ちすぎてしまって、少し後悔しました。

It works like:

• I ended up carrying too much luggage, and so I regretted it a little
• or Because I carried too much luggage, I regretted it a little

So the て-form here links actions/events and often suggests a natural flow or cause.

Because 荷物 is the direct object of 持つ.

• 持つ = to hold / carry something
• The thing being carried takes を

So:

• 荷物を持つ = carry luggage

Using が here would not fit the normal grammar of 持つ.

少し means a little or somewhat.

So 少し後悔しました means:

• I regretted it a little
• I somewhat regretted it

This softens the statement. It sounds less dramatic than simply saying strong regret.

Japanese often uses words like 少し, ちょっと, or 少々 to make a feeling sound more moderate or natural.

Because the speaker is talking about a past experience and their reaction to it.

• 後悔しました = I regretted it
• 後悔しています = I regret it / I am regretting it now

The past tense here presents the regret as something felt at that time, after realizing they had brought too much luggage.

The subject is omitted, which is very common in Japanese.

From context, we naturally understand that the speaker is talking about themselves:

• I went on a day trip
• I carried too much luggage
• I regretted it a little

Japanese often leaves out subjects when they are obvious from context. In English, you usually must say I, but in Japanese it is often unnecessary.