When the threat of an easily-transmittable virus hit the earth in 2020, every government reacted a bit differently. In Japan, where social eating is a profound part of the culture, the restrictions focused heavily on restaurants. The agreed-upon time was 8:00 pm. If your shop stopped serving customers by eight in the evening, you would get some financial assistance from the government at the cost of losing your evening customers. Some ramen shops, like Ru, took matters into their own hands by shifting their opening hours a few hours earlier. Breakfast ramen means an extra three hours of business to replace the three hours lost.
The breakfast ramen, like the heavy days of restrictions are more or less finished. You should still visit Ru.