The 'normal' ending of Grisaia no Kajitsu, set in Yumiko's route. The player can reach this ending by choosing 'Run away together' in the final choice selection screen in Yumiko's route.
While this is a normal ending that led to no deaths nor significant tragedy, it is meant to signify that pain and guilt can come from not just physical loss, but mental too.
Having decided to run away instead of confronting Michiaki, Yuuji and Yumiko end up on the run permanently, abandoning their previous lives and starting anew.
After several years, Yumiko and Yuuji have married and they now have a son. Yumiko had been disowned by her father Michiaki, indicating that he never had any interest in her as a heir to his company. Yumiko appears to be quite overjoyed about it, but Yuuji notes that he still sees that shade of depression looming over his wife.
While the both of them are not exactly living the good life, they have enough to get by with Yuuji's job and they still keep in touch with their old classmates, especially Amane. Nothing is known about Michiru, but it is known that Makina went to Kyoto to work together with Amane in her family's restaurant.
Yumiko continues to smile as their lives pass day by day, but Yuuji continues to notice that she constantly wears a mask of lingering sadness and loss, having been truly been abandoned by her father. Yuuji decides to confront her about it, and Yumiko reveals that she wishes to meet with her father again, even after all that he did to her.
Yuuji does not strongly object, but asks her why, to which she states that it is only normal for a daughter to want to show off her children to her father. They could even find the chance to rebuild their shattered relationship, thanks to Yuuji and Yumiko's son.
Yuuji agrees to her wishes, carrying both hope and despair in his heart, but he knew that what he felt could not be compared to the insurmountable loss that Yumiko must be feeling all this time.