What is the Independence Day that Inoue Marina has been tweeting about lately? Lately Inoue Marina has been tweeting about Independence Day. For example 2018-02-05 she tweeted,


  独立記念日全公演全て終了！
  今回は女子2人が交互にストーリーテラーとなっていく構成でかなりの集中力を要しましたが大変にやり甲斐のあるものでした。回を追う毎にキャスト皆の絆が深まって行って、とても素敵な空気感の中で幕を降ろす事が出来ました。
  来て下さった皆様、有難うございました！ https://t.co/CMlzcoSb7B


2018-02-04 she tweeted


  独立記念日1回目終わりました〜！
  あと2回！集中していきます！


and


  本日は砂岡事務所プロデュースリーディング公演、「独立記念日vol.2」です！ なんか今雪降ってきてビビってます。おそらくすぐ止むと思いますが。
  いらっしゃる皆様、お気をつけて！


2018-01-23


  砂岡事務所プロデュースリーディング公演『独立記念日』Vol.2の稽古が行われました。
  石川由依ちゃんと井上ってそれどこの進…というのは冗談として一緒に出演するのが由依ちゃんなのでめっちゃリラックスして臨んでおります。
  男性キャストの代永ウィング、福井貴一さんも滅茶滅茶素敵です！ https://t.co/Z1W6hVYdak


What is this "Independence Day" thing is about? Is it a Live movie? Does this means that she will become an drama actress now?
独立記念日 (Dokuritsu Kinenbi, Independence Anniversary*) is a live reading event produced by 砂岡事務所プロデュース (Sunaoka Creative Artist Agency, official website (Japanese)).

A short introduction on "what is a live reading?", it's a live staged reading event where voice actors and actresses read a story script live in front of audiences, or to put it simply, live audio drama. Live Read is one of such internationally-acclaimed events that can be found on Wikipedia.

Back to Dokuritsu Kinenbi, it's a 2-day live reading event which took places on Saturday and Sunday. There were 5 scripts: 2 scripts on the first day and 3 scripts on the second day. Each script consisted of 4 casts and took around 75~80 minutes without breaks. As it could be inferred from the tweet, it has been produced 2 times (as of Feb 2018):


Dokuritsu Kinenbi: 12-13 Aug 2017 (official site (Japanese))
Dokuritsu Kinenbi vol.2: 3-4 Feb 2018 (official site (Japanese))


This is how the stage for vol.2 looks like



From Sunaoka Jimusho's official Twitter account



*The English name is taken from these Facebook posts: Ishikawa Kaito and Hanae Natsuki