Heianjō tsuba, carved and inlayed in brass with a somewhat primitive design of rocks, plants, and waves, and a man in a boat beside two jakugo stone baskets on the face and a religious structure (stupa, grave stone) on the reverse. Muromachi or Momoyama period.

Size: 83.2 x 82.4 x 3.6 mm; 149.2 g

The Carlo Monzino Collection of Japanese sword fittings and swords (Sotheby's, London, 18 June 1996. p. 12-13) №9 provides an illustration of the similar tsuba with the following description: Heianjo tsuba, carved and inlayed with rocks, plants, and waves, also pierced with a jakago [sic] (stone basket).

Gary D. Murtha in his Japanese sword guards Onin - Heianjo - Yoshiro (GDM Publications, 2016) on page 53 shows a look-a-like tsuba (though, with a kogai-hitsu-ana) with the follwoing description: Iron, 77 mm, tsuba with brass tree, snake, jakugo baskets, and curved brass pieces (representing water flowing over rocks). Buddhist halo to reverse. Although showing Onin traits, a Shoami Heiamjo attribution would fit better. Azuchi-Momoyama period.

Iron tsuba with brown patina in mokkō-gata form with woven design. Size: 72 x 67 x 5 mm.

Six-lobed iron tsuba in a form of three ginkgo tree leaves (icho), separated with three small triangular openings (ko-sukashi). Leaves have raised rim and decorated with various family crests (mon) in low relief carving (sukidashi-bori). On obverse: bamboo stems and leaves, knotted geese, paulownia (kiri), plum blossom (ume), and ivy. On reverse: pine needles and cone, maple leaf (kaede), bamboo, stylized plum blossom, and Genji-mon. Black patina. Kozuka hitsu-ana is original, with raised rim. Copper sekigane. Kamakura-bori school. Late Muromachi period (ca. 1550). Size: Height: 81.1 mm. Width: 90.0 mm. Thickness at seppa-dai: 3.3 mm. Weight: 120.4 g.

Iron tsuba of six-lobed (mutsu-mokkō-gata) form, with six wild boar's eye shape (inome) openings (sukashi). Hitsu-ana and the entire perimeter of tsuba have typical for this school raised rim. Lobes are decorated with landscape motifs in low relief carving (sukidashi-bori). On the obverse: A hut under a full moon, Shinto shrine gates (torii) with pines and a full moon, rocks, a large pine tree, and a temple (pagoda) surrounded by rocks and waves. On the reverse: waves, fishing boat, wild gees in flight under full moon, maple, hexagon (tortoiseshell, kikko) with a dot inside and a dot outside (inclusion/exclusion symbol), and chrysanthemum (the last two may be family crests, mon). Kamakura-bori school. Late Muromachi period (1514-1573). Height: 64.2 mm, width: 74.3 mm, Thickness at seppa-dai: 3.2 mm, at rim 2.6 mm. Weight: 62.8 g (light). NBTHK old green certificate №561: Tokubetsu Kicho  - "Extraordinary Work". A look-a-like tsuba can be found at the Compton Collection, part II, pp. 14-15, №17, though his tsuba is more massive (80 x 84 x 4 mm). NBTHK paper says that the motif is Hakkei (八景), i.e. "Eight Views," so several interpretations are possible (the original Chinese ones, Omi Hakkei, etc.).  However, most likely it is the 'Eight views of Omi' (近江八景  - 'Omi Hakkei'). Why the artist selected a 6-lobed form for depicting 8 views remains unclear, and thus we are in our right to raise the question whether the motif is indeed Hakkei. The term Omi hakkei (eight views of Omi) refers to painting or print sets which illustrate life on the shores of Lake Biwa in Omi (now Shiga Prefecture). The model for such paintings came from China, where, from the eleventh century onward, painters had produced eight views of the Hsiao and Hsiang lake areas of Hunan Province. The themes, which follow the original Chinese models, are: geese descending to land, returning fishing boats, clearing rain, a snow-covered evening landscape, the autumn moon, night rain, a temple bell at evening, and the glow of sunset. Japanese artists have also used the eight-theme approach for other parts of country - including cities - and applied it to subject matter other than landscapes. [Merrily Baird. Symbols of Japan. Thematic motifs in art and design. Rizzoli international publications, Inc., 2001, page 308-9]. Japan Encyclopedia by Louis Frédéric also mentions Omi Hakkei as "Eight landscapes of Omi", and states that this theme was often cited in poetry after 1500. It is likely that the tsuba in focus is designed under the influence of the theme popularity in the 16th century. The theme was effectively exploited by prominent ukiyo-e artists Suzuki Harunobu and Utagawa Hiroshige in the 18th and 19th century, respectively. These are the eight scenes of the theme (see Wikipedia):

• Returning sails at Yabase (矢橋の帰帆) - Yabase. Yabase is an old harbour on the east side of the lake. Near the Tokaido, it was used for a shortcut to Otsu by boat.
• Evening glow at Seta (勢多（瀬田）の夕照) - The Chinese Bridge at Seta. The long bridge across the Seta was used by the Tokaido. In the background the "Fuji of Omi", the Mikamiyama. It is just above 400 m, but indeed well visible.
• Autumn moon at Ishiyama (石山の秋月) - Ishiyama Temple. The Ishiyamadera was located on a hillside next to the Seta River. It got his name form the strange rocks on which it is built, partly on supporting beams. A hut at the upper end of the site allows a view of the lake, and the moon.
• Clear breeze at Awazu (粟津の晴嵐) - Awazuhara. Awazu is well known for its pine wood, Awazu-ga-hara.
• Evening bell at Miidera (三井晩鐘) - Mii-dera. Miidera temple was built in the 8th century. Its famous bell is one of the "Three bells of Japan", the other two being those at Byoodo-in, Uji and at Jingoji, Kyoto.
• Evening rain at Karasaki (唐崎の夜雨) - Karasaki Shrine. Karasaki is a small cape with a single large pine tree, a hitsu-matsu.
• Wild geese returning home at Katata (堅田の落雁) - Ukimido. Alighting geese cannot be seen always, however the little temple near Katata in the square hōkyō-style, detached from the lakeside, connected by a bridge. The first part of the name uki is the same as in Ukiyo-e, meaning floating. Midō means temple.
• Evening snow at Hira (比良の暮雪) - Hira Mountains. The Hira mountains on the west side of the lake experience the hard winter, when the winter monsoon brings much snow from the continent.

In any case, as a conservative, I say that it is a landscape motif and a late Muromachi period work, rather than Omi hakkei motif and a mid-Muromachi work.

Thin six-lobed iron plate of brownish color is carved on each side with a groove that follows the rim and a concentric grooves around the center of the plate, also carved with six thin scroll lines (mokkō or handles, kan) that follow the shape of the rim. Mokume surface treatment. Hitsu-ana  possibly added at a later date, and kogai-hitsu-ana plugged with gold. Silver sekigane.

Signed: Kunihide [國秀]. Higo school, 1st generation swordsmith.

Mid Edo period, ca. 1800.

Would be possibly attributed to Kamakura-bori school revival of the 19th century.

References: Nihon Tō Kōza, Volume VI / Japanese Sword / Kodōgu Part 1, page 231: Enju Kunihide, a tōshō from Higo: "...forging of the jigane is excellent, and there are also pieces with mokume hada."

Haynes Index Vol. 1, p. 741, H 03569.0: "Enju Kunihide in Higo province, died 1830, student of Suishinshi Masahide. Retainer of the Hosokawa Daimyō, etc."

Additional Information from Markus Sesko:  This tsuba indeed is made by Enju Kunihide, who in his later years signed the HIDE [秀] character as HI [日] and DE [出], as here: Size: 77.4 x 74.9 x 2.7 mm Similar pieces are: 1. In this collection № TSU-0341: Kamakura-bori tsuba with mokkō motif. Muromachi period, 15th - 16th century. 2. Dr. Walter A. Compton Collection, 1992, Christie’s auction, Part II, pp. 14-15, №16: “A kamakurabori type tsuba, Muromachi period, circa 1400. The thin, six-lobed iron plate is carved on each side with a wide groove that follows the shape of the rim, and with six scroll lines and a single thin circular groove. […] The hitsu-ana was added at a later date, circa 1500-1550.  Height 8.3 cm, width 8.6 cm, thickness 2.5 mm. The tsuba was initially intended  to be mounted on a tachi of the battle type in use from Nambokucho to early Muromachi period (1333-1400)”. Sold at $935. 3. And another one in Robert E. Haynes Catalog #9 on page 24-25 under №23: “Typical later Kamakura-bori  style work. This type of plate and carving show the uniform work produced by several schools in the Muromachi </em period. Some had brass inlay and others were just carved as this one is. The hitsu are  later. Ca. 1550. Ht. 8.8 cm, Th. 3.25 mm”. Sold for $175.