Previous answer is
Shu-Mei Sa (Sa Sadayoshi)

Special feature : This blade has Shu-Mei(red signature)"Sa".
But the NBTHK judged as Sa Sadayoshi.
The shape is nice and Okissaki dignified blade.
Sa Sadayoshi is descended from Sa Monji.
The many pupils(Yasuyoshi, Yoshisada, Kuhihiro etc) succeeded.
Sadayoshi's blade looks like Samonji. The work is nice.
We have no fault to find with this blade. This is a masterpiece of the sword.

1:It is rather easy to answer the blade is Nanbokucyo period
because the blade is oosuriage with deep sori and long ookissaki Boshi.
2:The Hamon is Sosyu den style maild wavy temper line with active thick nioikichi gunome midare
and soshi is active turns back which is typical Sa school.
3:This sword tang was written kanji Sa red color by some judge probably high ranking sword expert judge.
4:Ths sword consist of active part and mild wavy temper line like Masamune Sagami provice
highest sword maker.
The blade is healthy top ranking sword.

==============================================
Appraisal Quiz #392 (June 17th, 2016)
Who made this sword do you think ?
==============================================

Hints. ※The picture will be enlarged

Blade length :　48.4　cm or 19.05 inches.
Sori :1.3 cm or 0.51 inches.
Mekugi : 4　
Width at the hamachi : 2.65 cm or 1.04 inches.
Width at the Kissaki : 2.0 cm or 0.78 inches.
Kasane : 0.58 cm or 0.22 inches.
Shape : Regular size elegant shape Katana with large Sori.
There are Hi and engraving on both side.
Jigane : Mokume Hada well grained with Jinie attach.
The Jigane is beautiful. There are Utsuri.
Unfortunately there are rough texture. But the blade is old.
It is somewhat unavoidables.
Hamon : Bright Suguha Hamon. There are many Ko-Ashi.

================================================

Answer will be posted at next Appraisal Quiz.

================================================

(Please acknowledge not replying to mail about Appraisal Quiz by our convenience.)