一週間フレンズ。 (One Week Friends)
Examples
Volume 1
Lunch on the rooftop with 屋上
Kanji » Shelter and shops with 屋
一週間フレンズ。 » Volume 1 » Page 54
Volume 3
Losing all that built-up friendship with 水の泡になる
Idiom » All that effort for nothing with 水の泡になる
一週間フレンズ。 » Volume 3 » Page 51
Volume 6
Singing one song after another with 連続
Kanji » Continuation and connection with 続
一週間フレンズ。 » Volume 6 » Page 5