It is dificult to judge only from pictures.
What we have: no complete toshin, because suriage blade. No complete Nakago, because suriage.
What we have is a oshigata, some pictures and informations: prominent masame with fine ko itame, a suguba/ko notare in ko nie wich frayed slightly to the Ha (ko ashi, a little bit sunagashi and ha nie), there is a hakkake yakizume boshi.
Okay,fine, Yamato Hosho Style.
But i agree with the opinion of Barry Hennik and Andreas B.: there is not enough hataraki and prominent nie for a very good Hosho blade from the best times of this school.
The Masame is very wavy, this feature can find in later Hosho works and works of the Kunikane Ha. Yes, later Hosho´s are rougher, and there are often masaware, but the Kantei Blade shows very good and clear masame without masaware.
@Uwe, thanks for welcome!
If (ONLY IF) the sujigai yasurime is a part of the original tang (and this Yasurime looks very similar to the early Kunikane´s), this sujigai is only on Omote Side (Side who you can find a signature). Above and on ura side there are kiri. So i think the Nakago was filed to fit the Habaki ( when parts of original Nakago is much bolder than the new machi okuri area). Also, the Ha machi looks very "weak", and parts of hamon are very close to the Ha.