It's adapted from the manga Restart wa Tadaima no Atode (Restart After Come Back Home) and its sequel Restart wa Onaka wo Sukasete (Restart After Growing Hungry) by Cocomi.
His mother asked him not to be NEET. NEET stands for "Not in Education, Employment, or Training." Some adult people in Japan face the insurmountable challenges or traumatic events at the places of employment or education. Then, they shut down emotionally and mentally and go into the self-imposed exile for months. The Japanese word for such people is "hikikomori" which can translate literally as "pulling inward, being confined".
Based on manga "Restart wa Tadaima no Atode" by Cocomi (published January 30, 2019 by Printemps).