ガチ (gachi)

short version of "gachinko" means a game played earnestly.

This word comes from Sumo (traditional Japanese wrestling）.

But now people use "gachi" for anything done earnestly, extremely and so on.

e.g. gachi ota= well informed about something. ota is the short version of "otaku".

otaku= enthusiastic sub-culture fan (but it's not the only meaning...)

寝活 (neru katsu)

neru= sleeping, katsu= short version of activity (katsudou)

Many office workers don't have enough time for health care or beauty care.

They don't even have enough sleeping time.

So people take care of own body overnight while sleeping.

e.g. special stocking for swelling legs, hair treatment, supplements for intestines...

炎上 (enjyou)

enjyou= usually "go up in flames"

Recently people use 炎上 for blogs or Twitter and so on.

In this case, too many people criticize theose blogs so the person who owns the blog can't manage.

Many people tend to become emotional trolls in the internet community because they can be anonymous.

だてマスク症候群 (dahte masuku syoukougun)

date (dahte)= for show, masuku= mask, syoukougun= a syndrome

Many Japanese wear a mask for preventing spreading a cold or for pollen allergy.

But recently people who don't have any symptoms wear a mask too.

Because if they use a mask, they can hide their face and expressions.

So some people want to hide their face without using make up, others want to hide their ugly (they think) nose and mouth.

Many young people wear a "date masuku" in school too.

アラシック (arashikku)

ARASHI= Japanese famous idol group, +sick

People are almost sick because they love the J-pop band ARASHI so much.

ARASHI is part of Johnny & Associates Productions.

That company uses only male talent who can sing and dance as a unit. 

Many Japanese young girls or women like these members.

ツイドル (tsui doru)

tsui= short version of Twitter, doru= short version of idol

A person or a character who has many followers and is very populer on Twitter.

Japanese famous ツイドル (tsui doru) is ガチャピン (gacyapin).

He can do anything and has about 800,000 followers.

風評被害 (fuuhyou higai)

fuuhyou= a rumor, higai= damage

After the Earthquake, Fukushima Prefecture had some damage from the nuclear power plants.

And while other Japanese people should help these victims, some people are prejudiced against Fukushima people.

Because they think Fukushima people are radioactive and will infect other people.

Many Fukushima students have to move to other schools but they are avoided by the students at their new school.

Even adults, some taxi drivers refuse to drive people from Fukushima.

Also many people refuse vegetables from Fukushima or Ibaraki.

It's like what happened to Arab Americans post 9-11.