Houseflags of Japanese shipping companies

image by Jarig Bakker, 19 December 2005
Source: Brown's Flags and Funnels of Shipping Companies of the World [lgr95]

Sanko Kisen K.K. Formed 1934. Going by the emblem shown on the funnel of "Sanko Laurel" 8.12.98 the red circles of the target are of different widths, the outer being narrow and the inner two progressively wider. Brown 1982 and 1995 show a different flag of 4 white and 3 red horizontal bands, the 2 white inner bands being narrower, with overall the red bands and merging the red "target" but this is incorrect and this flag is that of Sanko Asia Line Ltd. which in 1997 became Sakura Shipping Co. Ltd. The actual thickness of the bands of this latter flag are not certain and I am unsure whether it was retained after the name change.
Neale Rosanoski, 5 March 2003

Sanriku Unyu Co.

As stated on this Japanese firm’s website, Sanriku Unyu Co., Ltd. was founded in 1941 with the purpose of extending the harbor transportation service in Shiogama port (presently named Sendai Shiogama port).

Established at Shiogama (Miyagi Prefecture, on the east coast of Honshu), Sanriku Unyu offers stevedoring, customs clearance, and harbour transportation (including terminal operating), acts as a shipping and freighting agency, etc. For details see left menu ‘Activities’; the ‘intermodal transportation’ subsection informs us that the company is part of the Kuribayashi Steamship group and there is a map showing land and sea routes.

The homepage sports a symbol or logo, in red, consisting of three interlocked triangles above two horizontal lines. (I am sorry to say that the meaning escapes me.)

A related (road transportation) company is Sanriku Yuso Co. Ltd, founded in 1977 to counteract slackening loading and unloading business due to developments in shipbuilding. Between 1988 and 2003 the number of Sanriku firms, now organized into a formal group, rose from twelve to twenty representing a wide range of activities including insurance, manpower supply, and industrial waste transportation.
Jan Mertens, 30 October 2007

Sanyo Kaiun Co. Ltd/Sanyo Shipping Co. Ltd

What I understand from the company website - not being able to read Japanese and the English site being rather modest - is that the company was founded in 1978, is established at Kobe, and has branch offices in Tokyo, Osaka, and Nagoya.

The firm’s activities are neatly listed: marine transportation; shipping agency; air cargo freighter; forwarding agency; and insurance agency. Shipping destinations are situated in East Asia, the Emirates, and North America (Pacific coast).

A very small house flag is shown on the first page of the company site (Japanese version): white, a large blue initial ‘S’ (no serifs) interrupting a horizontal blue stripe. Or, as it seems, a horizontally divided flag white-blue-white, the middle stripe interrupted by a large blue initial ‘S’ (no serifs).
Jan Mertens, 9 November 2007

Seiwa Kaiun K.K.

image by Jarig Bakker, 8 September 2005
Source: Brown’s Flags and Funnels of Shipping Companies of the World, 1995 [lgr95]

Shikoku Ferry K.K.

image by Jarig Bakker, 19 November 2005
Source: Brown's Flags and Funnels Shipping Companies of the World [lgr95]

Shimazu Kaiun K.K.

image by Phil Nelson
Source: Flags, Funnels and Hull Colours, 1963 [ste63]

Shimazu Kaiun K.K. formed 1950 its fleet from 1998 appeared under Sun Marine Ltd. but there is no indication of the relationship between the two.
Neale Rosanoski, 5 March 2003