One of Witch Cult Translations' translators created a full translation of arc 4. As he states many times, his translations are not a perfect 1:1 translation, but rather a very detailed summary. He is only known by his email, ankaa.burner@gmail.com. His translations can be found here.
u/LawlessRaptor99 created a full arc 4 PDF using their translations. That can be found here.
Chapter 115: You Are Never A Match For The Girl From Your Youth
Chapter 116: With Grandmother, With Mother, With Sister; As Grandson, As Son, As Brother
Following Arc 4 is a series of interludes known collectively as One Day II, which take place between Arc 4 and Arc 5 (One Day I was the series of interludes between Arc 2 and Arc 3, the stories there are linked on our Side Content document).