Compared to its rugged stone exterior, the church’s interior is filled with decorative floral motifs. The pale moss green coved ceiling is supported left and right with numerous short beams, giving it the appearance of the keel of a boat.

There are no columns inside the church, probably in order to create as wide a space as possible. The corbel arches connecting the walls and ceiling are decorated with white floral motifs, with sky blue and pale pink accents, creating an overall pastel colour palette. One feels that being in this soothing space is something akin to being in heaven itself. The altar too has a unique design: just like the front of the church’s exterior, the altar also has an octagonal dome above it. If one looks closely at the details of this, the lower half is decorated with a floral pattern reminiscent of that of a Japanese-style flower planter. Compared to the western style pointed arches of the ceiling, here and there one can see the Japanese aesthetic presence in such rounded smooth lines. Furthermore, an almost identical altar to the one in Kashiragashima church can also be seen in an altar made at the end of the Taisho era which sits within Ebukuro church on Nakadori island. The possible connections between the two are intriguing.