The Former Mitsui Bank Otaru Branch, was designed and constructed by the Sone-Nakajo Architecture Company, a leading architecture company in Japan at that time. The building was erected in 1927(Showa 2), and was in business as the last metropolitan bank in Otaru, until 2002(Heisei 14). Hanaoka stones from Kitagi Island, Okayama, were used for the exterior, with plant-like motifs adorned the eaves. It is a reinforced concrete building, which was incorporated after the Kanto Earthquake in southern Japan, and was at the time, considered a cutting-edge aseizmetic structure.

The Former Hokkaido Takushoku Bank Otaru Branch, was built by the Architecture Department of the Ministry of Finances, lead by Kenichi Yahashi, who was at the time a prominent architect, worked for the building and repairs department of the government, and was involved with the construction of the House of Parliament. The building, reinforced concrete structure, was completed in 1923(Showa 12), and showcases impressive cylindrical pillars at the entrance, and a colonnade inside the sales department. It is a known fact, that in the year following completion of the building, the famous writer of proletarian literature Takizo Kobayashi, worked as a banker at the Takushoku Bank. The many other bank buildings nearby, which were built around the same time as this, give indication of just how dynamic the economy in Otaru was at that time.

The former Naniwa Warehouse is a timber-framed stone structure warehouse building, built on the banks of the canal in 1925 (Taisho 14), two years after the completion of the Otaru Canal. It was once established in Otaru as one of the businesses of Suzuki Shoten, which was called one of the three major trading companies along with Mitsui & Co. and Mitsubishi Corporation. It is a large-scale building among the warehouses remaining in Otaru City, and was designated as a Otaru City Designated Historic Building in 2012.