During the latest spread of the coronavirus, I often asked to myself whether I should do anything different from on-going studies. And, I haven't changed anything until now. Because the invasion of the virus has not inspired me with anything new or creative on my studies. It is just a new disease that is to be overcome finally, and it is a new problem that can and must be solved. All I have to do is to keep going on my studies on which the virus has not given any impacts. Meanwhile, environments outside have changed dramatically, and have had a variety of impacts on my research. A series of conferences have moved to fully virtual formats. Some of them have been shocked and shaken with this great impact: many times of extension of due dates for submission, and sudden closing of submission sites without a notice of no-extension. Some conferences still struggle for holding physical attendance in person at prospective venues. Everything is in turmoil at the present. What is a good way to survive this situation? Perhaps, it is simple: To do what you have done dairy.