So once again both Kaisei's are in, so you can either differentiate it by their kanji (開星 from Shimane, 海星 from Nagasaki), or just make that delineation beforehand.
Now, they did struggle out of the gate against Sasebo Kougyou, but otherwise breezed through the prefecturals and included a win against Nagasaki Nichidai. They then proceeded to blow out former Koushien participants Kounan and Kitsuki before holding on against Kagoshima Jitsugyou (another Koushien regular) to reach the finals... where they were then promptly blown out.
So, they racked up some quality wins there, but the blowout might hurt if they were actually trying (remember by the finals they should have earned an invitation, so more work isn't necessary). And after ace Harada was relieved early in the game, they sent in other pitchers instead and probably just made sure to finish the game without injury or giving away scouting info.
So, about ace Haruta Tsuyoshi (春田 剛志), I don't have any info on him - despite this team being the runner-up in the Kyushu Super-Regionals. There might be a reason though. In his last 2 games he worked 0.2 IP against Kagoshima Jitsugyou and gave up 2 runs. Then against Shuugakukan, he gave up 3 runs in 3.2 IP. If he's the ace, this is concerning.
And none of the other pitchers fared better either. The next man up looks to be Tsuchiya Kazushi (土谷 一志), who fared much better against Kajitsu (1 run after relieving Haruta), but then gave up 2 as the last reliever against Shuugakukan. Kan Yuusuke (間 悠亮) and Hiromori Yuuto (広森 悠透) did not fare much better in the finals.
This means the offense is under a lot of pressure to make up for the apparent average pitching. CF Hattori Takahiro (服部 貴大) leads off a top-heavy lineup along with 3B Shimabara Yuuki (島原 勇樹), and C Tagawa Kenta (田川 賢汰). But the power outages against some of the well-known schools is a big concern and will present challenges right off the bat - especially with even a worse-than-average draw.
Which means their prospects are much reduced in my opinion.