You might want to look at the Ryobu-kai style. The founder of this style was a student of Morihei Ueshiba and O Sensei had a hand in advising him in the development of a couple of the later katas. These articles below are from the Ryobukai website.
The JAPAN KARATE-DO RYOBU-KAI (JKR) is a professional, international organization under the leadership of Yasuhiro (Takehiro) Konishi, 10th Dan.
The JKR has branches located all over the world under the guidance of Kiyoshi Yamazaki, 8th Dan, International Director and Chief Instructor. The style of karate taught by the JKR is called Shindo Jinen Ryu. This style was founded by Yasuhiro Konishi, who learned karate from Gichin Funakoshi, Chojun Miyagi, Kenwa Mabuni, and Choki Motobu. Additionally, Konishi Sensei studied extensively under the founder of Aikido, Morihei Ueshiba.
The JKR also has a lineage dating back to the 16th century traditions of Takenouchi Ryu Jujitsu. Training in the JKR is conducted in the traditional Japanese method, stressing discipline, consistent attendance, etiquette, and hard work. The karate training in the JKR is life-long, and can be continued regardless of age.
Modern training in Shindo Jinen Ryu Karate-do incorporates elements of karate, aikido, jujitsu, and kendo in the formal curriculum, with an emphasis on philosophy and education. The curriculum also emphasizes Zanshin (the ability of an exponent to gain dominance over an opponent through an alert state of mind) and maintenance of proper physical posture.
The purpose of training in Shindo Jinen Ryu Karate-do is to develop the whole human being, physically and mentally. Through long-term, dedicated training the student learns to develop and unite Shin (mind), Gi (technique), and Tai (body)
in proper proportions. The end result is awareness of one's moral obligations and place in society.
Though Ryukyu traditional martial arts, Ryukyu Kenpo Tote Jitsu, and Karate-jitsu had started to be known throughout Japan, the history of its dissemination in the mainland Japan was still short and it could be said that they were considered to be by far inferior in every aspect of martial arts to Kendo and Judo.
The fact that Karate was still called "Karate-Jutsu" while Kendo and Judo were called with "Do" indicating the system. With a strong desire to develop the karate into one of the recognized martial arts by all means. Yasuhiro worked very hard to disseminate karate through the connections in the Jujitsu world. But the results were not satisfactory one. In the Kendo world, people who recognized karate like Hakudo Nakayama was a minority, and there was still a strong tendency to define karate a primitive art in which thrusting and kicking were representative arts. If someone remarked that karate was a kind of fencing without a sword, a lot kendo masters showed a fight against that kind of remarks. From the end of the 1920s, many people pointed out that not a few karate men lacked good manners and behavior. People who were in the Judo world denied unanimously the existence of karate, and there was even a movement in Kodo-kan which tried to introduce the karate into a part of Judo as a self-defense art. The reason why Gichin Funakoshi declined the frequent invitation to the Kodo-kan had a strong relationship with this.
Also the various schools of traditional martial arts didn't give any high evaluation of karate. "Essence of Japanese traditional martial arts was not to defeat the opponent completely, but to pin down or hold an outlaw asking him whether he would correct his conduct or not, and if not, arm or some parts of body would be dislocated, which meant a spirit of allowance to forgive the enemy was left even in the fight. "On the contrary", some of the traditional martial arts masters protested Yasuhiro saying that "karate stars abrupt thrusting or kicking. This is against the code of behavior for SAMURAI spirit." This kind of criticism was not so serious. But the more severe criticism generated by one of the martial arts experts was that forms of karate were not refined historically. This comment hit the weakest point of karate. Expert who made this comment was Morihei Ueshiba who developed Aiki-do later. This martial arts expert was standing unrivaled in the term of the strong and mysteriousness in Te beginning of Showa era together with the fact he mastered various martial arts such as Yagyu-Ryu, Hozoin-Ryu, Jyuken-Jutsu, and other traditional Japanese martial arts concentrating on Aiki-do Jujitsu of Daito-Ryu.
One anecdote tells that he didn't give any chance to a plural of high ranking kendo experts to hit him when he had a match fighting with them, and another anecdote tells that when he was surrounded by a plural of military polices, he disappeared instantly without being observed by the military polices, and another anecdote tells that when he fought with a grand champion of Manchuria wrestling, he threw the opponent with his little finger, and one of his followers Kozo Shiota a master (manager of Yoshinkan) observed Ueshiba fight with "Piston" Horiguchi a boxer holding down the opponent forward instantly with his little finger. Anyway, he was a first ranking martial artist who was referring to as "God of martial art".
Yasuhiro also entered in his club, but as Ueshiba didn't make any official announcement of Aikido developer yet at that time, the list of license for Yasuhiro which is still preserved carries "Daito-Ryu" and "Aioi-Ryu". When Yasuhiro demonstrated "kata of Heian" Shodan (now Nidan), he was suggested by Ueshiba to discard such martial arts because it didn't work at all. Later Yasuhiro commented that the most great and unrivaled master of martial arts I met so far (he was 83 years old at that time[c. 1973]) was Ueshiba Sensei.
But Yasuhiro's karate was entirely criticized by this great master whom Yasuhiro respected much. The point of Ueshiba's criticism was that "the martial arts with only rough and straight attack doesn't provide any usefulness...." To Ueshiba who believed that only circle movement was the ultimate goal of martial arts, straight attack such as thrust and kick seemed to be mastered quickly, but he could not feel any profoundness in the art and it seemed to him that the art couldn't catch up with the nobleness the martial arts should have at all. Yasuhiro explained the situation later. "I wouldn't like to stop my karate even if I was suggested to stop it because it didn't work out at all. I had responsibility for developing the karate into the recognized martial arts some day with the help of Aiki-do which would be accepted by my teacher Ueshiba. I was planning to show him my karate again, so I asked him to never mention to stop right away." (From memories of Yasuhiro on Karate).
Yasuhiro tried his best to find out the best solution to the above for almost eight months. "Ueshiba was a man having a divine inspiration rather than a man of martial artist. And he seemed a special man to me. His life was full of curious things. Therefore, I admired him and believed in him and what he said was my mental food and I tried by best so that I could be accepted by him." (memories on Karate by Yasuhiro). And when Ueshiba saw demonstration by Yasuhiro which was quite familiar to kata form of "Heian", he was satisfied and said tapping his laps "Mr. Konishi, the demonstration you did now was satisfactory to me, and that deserves well for mastering." This form which was demonstrated by Yasuhiro was developed and referred to as "TAISABAKI" body movement later. "Though it contained no complex movement, the form was consisted of continuous movement instead of pausing after each action. That is to say, the form didn't employ any single action, but employed a chain of action without pausing between them. Not an accumulation of single action, but a flow of movement. The demonstrations I had ever seen were a spell of movement like a puppet doll as Ueshiba pointed out."
At the same time, it is said that Yasuhiro learned from Ueshiba that the art had two kinds of spirit, one expressed externally and one expressed only in mind. Yasuhiro's incessant eagerness to acquire the secret of various kinds of martial arts brought him the chance to meet Seiko Fujita, the 14th generation of master of "Koga Ninjutsu" and made him to obtain the license from "Nanban Kito-Ryu", and to meet Motoro Kaneda of Yoshin Koryu", and made him to learn swift technique from Haunari Watanabe of "Shiba Shinyo-Ryu Jujitsu" and "Fusen-Ryu Jujitsu" from Eizaburo Nakayama and "Yagyu Shingan-Ryu" from Itsumi Sato.
The author has never heard any one who mastered so wider variety of martial arts as Yasuhiro Konishi. Yasuhiro learned the martial arts other than karate and tried to compare them with karate and adopted the arts which did not exist in the karate. His method was to employ the excellent skill form other sections of martial arts and discard what was not useful to his karate to attain the balance combination of various techniques in his karate. Everybody asked "Why are you so eager to acquire the secrets of other martial arts than karate?" He always replied that "I would like to improve karate to the level equal to Kendo and Judo which were traditional Japanese martial arts."
Seiryu - The Story Behind the Kata