Yamahome-sai
The Yamahome-sai is a festival held two times a year, in April 15th and November 15th. It is a ritual ceremony to "praise" the three mountains behind the shrine, Katsuyama, Kinugasayama and Mikasayama, to thank for the blessings from the mountains and sea. The spring festival, called Yamahome-tanemaki-gyoryō-sai, is to wish for a good harvest and good catch of fish, The autumn festival, called Yamahome-karisunadori-no-matsuri, is to thank for the years harvest and protection. After some rituals are performed at the honden and the Imamiya shrine, a ritual ceremony to praise the three mountains are performed at the yuniwa , beside the Castanopsis tree brought from the mountain. A scene of scattering seeds from the Ikumin-bashi is also performed in the spring festival.
The origin of this ritual is unknown. However, it is said that the people of Shikanoshima performed this traditional ritual in front of Empress Jingū when she was about to go on her conquest to Silla. She told the people to hand down this ritual unless the waves washing ashore on the island stops, and patronized the ritual warmly.
In the Yamahome-sai a scene of going out to sea and fishing sea breams is performed. In the address made in this scene, the lyrics of the "Kimigayo", the national anthem of Japan, appear in the beginning.
君が代は 千代に八千代に さざれいしの いわおとなりてこけのむすまで
あれはや あれこそは 我君のみふねかや うつろうがせ身骸に命 千歳という
花こそ 咲いたる 沖の御津の汐早にはえたらむ釣尾にくわざらむ 鯛は沖のむれんだいほや
志賀の浜 長きを見れば 幾世経らなむ 香椎路に向いたるあの吹上の浜 千代に八千代まで
今宵夜半につき給う 御船こそ たが御船ありけるよ あれはや あれこそは 阿曇の君のめし給う 御船になりけるよ
いるかよ いるか 汐早のいるか 磯良が崎に 鯛釣るおきな
It is said that the source of reference of the lyrics of "Kimigayo" is the waka, of an unknown author, recorded in the Kokin Wakashū. However, there is a theory that the Kagura-uta was spread by traveling entertainers, and as a result, it was recorded in the Kokin Wakashū. A similar Kagura-uta is also handed down by Najima shrine, in Fukuoka city, and Fūrōgū in Ōkawa city, those are also shrines deeply related to the Azumi clan.
Oshioi
Since the main dieties of Shikaumi shrine, the Three Watatsumi gods, are gods those appeared during a misogi, ritual for purification, it is said that the gods particularly dislikes impurity. Therefore, when visiting the shrine, one must purify their mind and body not just by chōzu like in other shrines, but also using purifying sea sand called "oshioi".
There is oshioi at the entrance of the shrine and at the haiden, so one should sprinkle some oshioi, first on the left side of the body, then right and left again.
The oshioi in front of the juyosho can be taken home.
those who are in Mourning, during menstruation or pregnancy, babies within the first 100 days of life are request not to visit the shrine. It is because, in Shinto, death and blood are considered to be kegare.
Kame-ishi
When Empess Jingū was about to go on her conquest to Silla, she prayed through Azumi no Isora, beside the two ponds, Kamegaike and Kamezumīke, in Uchiage-no-hama, that is estimated to be Uminonakamichi, so that she can return safely. After performing kagura for 7 days and 7 nights, Shika-myōjin and Katsuma-myōjin appeared on two golden male and female turtles. The two gods gave Empress Jingū the two balls with spiritual powers, the Kanju and Manju, protected and lead her ships. The turtles were set free at the Kamegaike and Kamezumīke, and is said that they appeared again as rocks where Kin'in park is now. These rocks were dedicated to the shrine in 1671 and are now placed in the yōhaijo.
Kotonakishiba
After safely returning from her conquest to Silla, Empess Jingū had a festival in appreciation. As a part of that, she dedicated a handle of a helm, made from Castanopsis, and stuck it in the forest in Katsuyama, where Shikaumi shrine is. Later, leaves sprouted from this handle, and became to be called "Kotonakishiba". "Kotonaki" means "uneventful", and "shiba" is Castanopsis. It has been believed that who took a leaf of the Kotonakishiba when going out, would return safely.
In the Tanabata festival, fishermen from all around the Hakata bay area gather to pray for safe fishing and a big catch of fish. After prayers, they would receive a Kotonakishiba made from a branch of a Castanopsis tree and Shika tea, and is believed that who took a leaf of the Kotonakishiba with themselves when going out fishing would come home safely. After a year, the Kotonakishiba would be returned, in appreciation of a safe year, and recieve a new Kotonakishiba.
Commonly, Sakaki trees are used for rituals, but in Shikanoshima, Castanopsis trees are used in the place of Sakaki.