There's not much of a party scene in Hirajiro, so the stores don't carry traditional glow sticks. They do have some glow in the dark toys, though, so you can always fill a jar up with little glowing dinosaur figurines and it's sort of the same thing... though they will dim significantly (but not completely) during Lockdown.

For other options of light that work during Lockdown, there's the Black Raven lanterns (and the lanterns that burn for a week as a reward for request 07) and the Amemasu scales (and the mirror as the reward for request 08) from the school and lake dungeons respectively.