Blade construction: Hira zukuri, Mitsu-mune, No curve. Wide in Mihaba, thick in Kasane leading to a wide upper Fukura in full. Full at "Hamachi" with an original cutting edge so called "UBU-HA" and deep at back edge "Munemachi".(click HERE for higher resolution image of the entire blade).
Forging(Hada): Clear Ayasugi-style hada ware. Hiraji is covered in abundant Ji-nie glitter to generate darkish ranging swirl hard metal stream so called Chikei activity. Dramatic and vivid scene of Jihada - grand sight.
Temper(Hamon): Hamon forms Suguna straight in general, mixing in minute irregular gunome-shape. Temper edge is covered with sparkling Nie granules and shows abundant activity of Uchinoke, Kinsuji, Inazuma, Fish-hook shape and Sunagashi frequently that are harmonized with Chikei swirling pattern in Hiraji surface.
Temper of tip(Boshi): Blazing up Kinsuji Nie-lines activity small circle turns back.
Tang(Nakago): Nakago is in UBU original. One peg hole. Kurijiri round bottom shape. Osujikai (greatly slanting left) with Kesho (horizontal) filemarks.The signature in front starts with with the pseudonym of Yusuishi 湧水子 and the smith name SADAYOSHI 貞吉. The reversed side is chiselled with the date of year In the 1st month, the 45 year of Showa and owners name Yamamoto Noboru korewo Shoji 昭和二二十五年正月日　山本　昇　取持之.
This is the tanto work by Enomoto Sadayoshi 榎本貞吉, real name is Enomoto Yoshiichi 榎本吉市 who was born in January 22, 41th year of Meiji (1909) in Tokushima prefecture. He studied under Gassan Sadakatsu 月山貞勝 since the 3rd year of Showa (1928).
He had succeeded the Gassan style Ayasugi wavy forging technique then moved to Mishima city in Shizuoka prefecture in the 18th year of Showa (1943). He went to win many prizes at the NBTHK competition and enjoyed a Mukansa treatment in the 56th year of Showa (1981), then officially was designated to the top level professor of Mukansa award in the 8th year of Heisei (1996). To achieve a Mukansa title, one have to win an assortment of the eight top prizes, so it usually takes may years or decades under fierce competition.
Under Gassan Sadakatsu's pupils, he is known as an expert of beautiful Ayasugi-style forging, next to the Natoinal treasure swordsmiths, Gassan Sadakazu and Takahashi Sadatsugu.
The skin of this tanto shows his typical example - a very clear and vivid swirling Ayasugi-hada that gives off close resembles to the ancient work of Gassan school. Carefully crafted tang and skillful chisel of signature are favorably impressed. Died at 91, in 2000.
[genealogy : Suishinshi Masahide 水心子正秀→Gassan Sadayoshi 月山貞吉→Gassan Sadakazu 月山貞一→Gassan Sadakatsu 月山貞勝→Yusuishi Sadayoshi 湧水子貞吉）
Preserved in a new Shira-Saya plain wood mounting Gold foiled copper Habaki collar (copper ground repaired and some of gold foil are teared off).
Recent elaborate polish/Condition scale: mint (using a scale of mint-excellent-very good-good-fair-poor).