It is really hard to make a Japanese style packed lunch box.
Depending on who you are talking to you can use either of the sentences above. If i is someone form Japan, you can say "It really hard to make a bento (lunch box)." or if it someone who is not from Japan and doesn't know what bento is you can say "It is really hard to make a Japanese style packed lunch box."
あなたが話している相手によって、上記のいずれかの例文を使用することができます。日本出身の相手であれば、"It really hard to make a bento (lunch box)." （お弁当を作ることは本当に難しい）と言うことができます。日本出身でなく、お弁当がわからない人には、"It is really hard to make a Japanese style packed lunch box."（日本式のお弁当を作るのは本当に難しい）と言えるでしょう。
If you need skills for something, it already implies that the task is really difficult. Usually you would have to explain this phrase. It is common to have the association that skills are needed with hard work.
We use tricky for things that are a bit difficult or require a lot of time and attention.
もし、何か need skills（技術を必要とする）ということは、そのタスクがすでに難易度が非常に高いことを示唆していますね。
通常、このフレーズを説明しなければならないでしょう。
技術と同様、一生懸命行う必要があるということも関連づけておくのが一般的です。
難しかったり、時間や集中力が必要なものを扱うときに「tricky」を使います。
The Japanese-style lunch pack is quite tricky to make because it requires a lot of effort
The Japanese boxed lunch is not easy to make because it has many different food portions.
"The Japanese-style lunch pack is quite tricky to make because it requires a lot of effort"
This is an acceptable way of explaining how challenging making the Bento is.It would also be a good idea to explain the reason why it is difficult.
tricky= an adjective that means something is a challenge;not easy to do.
"The Japanese boxed lunch is not easy to make because it has many different food portions."
food portions = different kinds of foods
"The Japanese-style lunch pack is quite tricky to make because it requires a lot of effort"
これは、お弁当を作ることがどれほど大変かを説明するのに適した表現です。難しい理由を説明してもよいでしょう。
tricky= 何かが大変で、容易ではないことを意味する形容詞
"The Japanese boxed lunch is not easy to make because it has many different food portions."
food portions = 食品の種類
Making bento is not something you should undertake lightly
When preparing a bento lunch box there are a few things to be taken into account and though some people may take this task in their stride, others may face some personal challenges.
It is not necessarily a straightforward task.
'Straightforward' means that it is uncomplicated and easily achievable.
My worst challenge ever was making a Bento (lunch box).
I has never been easy to make a Japanese style lunch box (bento)
▪ My worst challenge ever was making a Bento (lunch box).
This explains that making a bento is a challenge. This means that it is difficult to make a bento and it is one of your worst challenges.
▪ I has never been easy to make a Japanese style lunch box (bento).
This indicates that making a bento (lunch box) has always been difficult and complicated.
▪ My worst challenge ever was making a Bento (lunch box).
この例文では、お弁当を作ることは大変であることを説明しています。 これはお弁当を作ることは難しく、あなたにとって大変であるという意味です。
▪ I has never been easy to make a Japanese style lunch box (bento).
この例文では、お弁当を作ることは難しく複雑であることを表しています。
Making a bento is not as easy as it sounds it can be quite complicated and challenging to say the least.
Preparing a Japanese bento is not as straightforward and easy as it appears.
I find it very challenging preparing a bento.
To express that something is difficult one might say that it is complicated, challenging, not as straightforward as it looks, hard, tough or even complex.
keywords:
complicated- Involving many different and confusing aspects.
challenging-Testing ones ability to perform a task.
not as straightforward as it looks- An expression that indicates that something is harder than it seems.
tough-difficult
complex-Not easy to do or understand.
何かが難しいことを表現するには、it is complicated, challenging, not as straightforward as it looks, hard, tough, even complexといった言葉を使うといいでしょう。
キーワード：
complicated- 複雑であること
challenging-その人のタスクをこなす能力をみること
not as straightforward as it looks- 見かけよりも難しいこと
tough-難しい
complex-それをしたり、理解することが簡単ではないこと
I thought I'd knock up a quick bento box; but I failed...its a tricky dish to make.
When something is said to be "tricky" it means it is "deceptive" ... even though it may seem simple enough...it is really "much more demanding" than we thought.
A bento box is a good example of this:-D It is a tricky dish to prepare;-D
Since there a several elements to consider and combining the "balance in flavors"
can indeed be .."a tricky business"
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