The development of molecular systems that enable the control of molecular movements, in particular, rotary and elastic (extension-contraction) motions triggered by external stimuli, is an urgent and expanding research area in supramolecular chemistry and nanotechnology owing to their potential application to molecular machines, such as molecular motors and springlike devices. [1] Although sophisticated biological molecular motors and springs exist in every muscle cell and function cooperatively to generate force and movement for muscle contraction by converting chemical energy into mechanical functions, [2] the control of unidirectional motions that further amplify to macroscopic movements with artificial molecular and helical systems remains a challenge. [3,4] Recently, we reported a unique optically active doublestranded helicate 1 a in which two ortho-linked tetraphenol strands with a biphenylene unit in the middle were bridged by two spiroborates that sandwiched a Na + ion between them (Figure 1 a). [5] The optically active helicate underwent sodium-ion-triggered, reversible extension-contraction motion coupled with a twisting motion in one direction upon the release and binding of the Na + ion (Figure 1 b). [5a] During this unidirectional springlike motion, the helicate maintained its helical handedness. [5a] Such ion-induced molecular motions are key processes in a number of biological events and reminiscent of biological machines that operate in muscle cells. [6] Biphenol (in 1 b) [7] and bipyridine groups (in 2) [8] could also be used as linker units to connect the two outer biphenol units and produce optically active double-stranded helicates similar to 1 a after conventional optical resolution; however, Na + ions coordinated in the center of helicates 1 b and 2 could not be released in the presence of [2.2.1]cryptand, which had been used to remove the Na + ion from 1 a, because the Na + ions were strongly bound by the biphenol oxygen and bipyridine nitrogen atoms as well as the spiroborate anions.Thus, no ion-triggered springlike motion was observed for 1 b and 2.With the aim of the further development of molecular springs that twist unidirectionally and perform intelligent functions, we designed and synthesized the porphyrin-linked, double-stranded spiroborate helicate 3 a Na 2 (Figure 1 c). We anticipated that the linker porphyrins introduced in the middle of the strands could stack face-to-face in a helical orientation and thus provide a chiral cavity for the further inclusion of electron-deficient aromatic guests, such as G1 and G2, by an induced-fit mechanism. [9] We hypothesized that the expansion of the bisporphyrin cavity upon the encapsulation of guests would be accompanied by a rotation of the porphyrin rings in one direction and a corresponding unidirectional twisting of the spiroborate helix. Thus, the helicate should be able to perform dual unidirectional motions induced by guest encapsulation (Figure 1 c). To the best of our knowledge, such stimuli-responsive unidirectional dual motio...