The novel concept of metascintllator, topologies consisting of heterogeneous scinitllating and light-guiding materials has been proved to achieve an equivalent CTR of 200ps for BGO-based set and 140ps for LYSO-based set even with an non-optimized configuration. In this work, we evaluate a novel architecture: The principle is to slice a slow scintillator (BGO or LYSO) monolithic in thin slabs, then interlaeve them with thin segmented fast scintillators (plastic EJ232 or EJ232Q), and finally couple them to an array of SiPMs, in what we term semi-monolithic meta-scintillator (SMMS). As the fast scintillator retains an 1-to-1 coupling with independent SiPMs, fast photons are contained within the limited space and statistical variation is similar to that of single pixel. At the same time, photons of the high-Z material are distributed over the SiPM array, providing Depth-of-interaction encoding according to the semi-monolithic paradigm. We combine layers of slow scintillator of dimension 0.3 x 25.5 x 15.0 mm3 or 0.2 x 25.5 x 15.0 mm3 and layers of fast scintillator of dimensions 0.1 x 3.1 x 15.0 mm. We used the Monte Carlo Ray-Tracing Gate simulator to study and investigate the performance of this new type of semi-monolithic. Based on the simulation results, it is shown that the time resolution of semi-monolithic metapixel is equivalent to the single metapixel with the same scintillator mix. In particular, LYSO based designs lead to an overall DTR of 80 ps after implementation of timewalk correction, while BGO based designs lead to equivalent DTR of 160 ps. On top of that, the detected visibly variable photon distributions along the SiPM array, which allow a determination of the depth-of-interaction with < 3mm precision leading to a detector cell of 3x3x3 mm3, combining such element size with ToF capabilities in a cost-effective design.Further developments include the implementation of machine learning for further improving both DoI and ToF performance of the SMMS.