The first book in the series, explains the foundation of the Aiki Secrets architecture
At the 'center' of this is the explanation of your 'Center of Balance' i.e., the COB. Awareness of the COB is critical to applying the first Aiki secret: 'Pin and Spin'
"Six Precepts" begins with a series of short stories called 'Basic Terms' that lay the ground work for studying the six precepts. These 'Basic Terms' are snippets of precepts. Important facets of performing Aiki are found here.
The "Six Precepts" are then explained within the groupings of 'Where Uke Is Weak', 'Where We Are Strong', and 'Connection Builders'
The book culminates in an explanation of the primary secret of Aiki: 'Pin and Spin'
Within this secret is the core understanding of how to control your and your opponent's stabilityA further look into "Six Precepts" is here
The second book, expands upon the previous work to include more 'secrets' and how to apply them.
Following the familar pattern of 'Basic Terms', 'Where Uke Is Weak', 'Where We Are Strong', and 'Connection Builders', Aiki Codex: The Secret to Circular Aiki opens up the perspective of Aiki as simple machines; machines we can emulate with our bodies
In "Aiki Codex", the 'Basic Terms' describe a number of body mechanics. These concepts are 'Precepts in action'. The short stories reveal sensations and/or alignments necessary to understanding the upcoming 'Advanced Concepts'
In 'Where Uke Is Weak', we perfect the awareness of 'The 20' introduced in the earlier book, learn Uke's weaknesses when standing with weight positioned on one leg, and then give a detailed and profound explanation of using joint-locks to create Aiki. 'You will only read it here' information at nearly every turn
'Where We Are Strong' lays the foundation for finding 'Internal' strength both mentally and physically. Mind-Body awareness development, body structuring, using ligaments to grasp items/opponents, and amplifying your strength by creating levers within your body are made understandable, achievable, and powerful
Advanced Connection Builders culminates in the explanations of 'Rolling' and 'Orbits'. Rolling is the arguably the greatest of all Aiki secrets, and Orbits, used prolifically in 'big circle' type Aikido, is the heart of the chuan in an 'internal' Chinese art called: Ba Gua. Expect these two 'secrets' to lay the foundation for upcoming content...A further look into "Aiki Codex" is here