Regarding 海蛍 Umi Hotaru

Dark, moonless nights are best. Sea fireflies are found only in beautiful seas with sandy bottoms, up to three to five Hiro (a unit of measurement) deep. If there’s a protruding dock or similar structure, it’s especially good. Cut the heads of bonito, yellowtail, or mackerel in half, thread them, and throw them into the sea. Lift them after counting to 500 to wash off in a bucket of seawater. Put about twenty in seawater, lift and collect them one after another.

To keep them alive until the next morning, use a box that allows seawater to flow through well but doesn’t have gaps larger than 一分 one Bu (3.03 mm); otherwise, they might escape into the sand. Don’t forget this.

In the morning, separate them from fish flesh using a sieve (if separated when collected at night and placed in another box, it’s even better), lay them on a fine net, and dry them in the morning sunlight. They dry in about a quarter or half an hour; the shell becomes transparent, and only the white, opaque ones won’t glow. Bad.

– Good for use against rats, large birds, and insects (this is unclear). Oral tradition. Be careful when it rains; they can wash away and be ruined.

– If there’s no water, urine is also fine.

– Discuss the method of attachment with allies.

– To inform those coming later.

– For use on the way back. In places invisible to the enemy but visible to the infiltrator, bad places, good places (when facing the enemy outward), west, near the entrance of lavatories, from that place visible, rarely visited by people but clearly visible, inside a pond (moats are bad because they’re too wide), under eaves, under the floor, at the folding point of a ladder ascending from below, at a stone dropping point.

About 海蛍 Umi Hotaru on night paths.

– Apply at the base of trees. Even if it rains, the water sliding down the tree won’t wash it away. Heavy rainfall is bad for the base of the tree.

– If it’s raining heavily, break a branch and attach it in the direction of the path. Tie the branch above where the firefly is attached. When returning from a ninja mission, remove it. Fireflies are good.

– When water is added, they can glow for about one and a half minutes per inch and minute. Good in spring, autumn, and winter; in summer, they last for about a quarter of an hour. Good.

– High places (climbing up to attach takes time), low places are easily discovered. However, since Yasuda-ryū’s fireflies are used at night, one foot above the ground is best.

– To inform and communicate with those coming later. Use standing 1, 2, 3, horizontal 1, 2, 3, L-shaped 1, 2, 3, circle (draw thickly) 1, 2, 3, “me” 1, 2, 3, all types of combinations. Windmills are good in windy conditions – spinning fire (used in high places) is very good.

– Decide the length of the string based on the wind’s strength. No fireflies on the back.

– Attach to a tree branch. With the wind, it spins, having fireflies painted on one side only, so it appears and disappears. Do not attach within reach.

– To distract the enemy or as a sign for allies. Decide the length of the string based on the wind’s strength.

– For transport, just roll it up.

– Dark nights are preferable, but if there’s a moon, the lower, darker spots are best.

– High trees within a forest are very good. However, decide by throwing a string over them. But it should be visible from below.